MX2008006863A - Identification of protective antigenic determinants of porcine reproductive and respiratory syndrome virus (prrsv) and uses thereof - Google Patents

Abstract

The invention relates to a polypeptide of a protective antigenic determinant (PAD polypeptide) of porcine reproductive and respiratory syndrome virus (PRRSV) and nucleic acids encoding a PAD polypeptide. The PAD is generated by a heterodimer consisting of the GP 5 protein and the M protein of PRRSV wherein the ectodomain of GP 5 has different N-glycosylated states. The PAD polypeptide and nucleic acids encoding a PAD polypeptide are useful in the development of antibodies directed to PAD, vaccines effective in providing protection against PRRSV infection, and diagnostic assays detecting the presence of PAD antibodies generated by a PAD-specific vaccine. The invention also discloses methods of generating antibodies to PAD, for vaccinating a pig to provide protection from PRRSV infections, a method of preparing the vaccine, a method of treating PRRSV infections in a pig, and a method of detecting antibodies to PAD of PRRSV.

Description

IDENTIFICATION OF ANTIGENIC DETERMINANTS THAT PROTECT THE VIRUSES OF THE PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME, AND USES THEMSELVES FIELD OF THE INVENTION The embodiments of the invention generally relate to the field of porcine reproductive and respiratory syndrome virus (PRRSV) and more particularly to the discovery of a new protective antigenic determinant (PAD) of PRRSV and its use in vaccines, treatments and assays. of diagnosis.

BACKGROUND OF THE INVENTION In 1987, the pig producing industry in the United States experienced an unknown infectious disease that had a serious economic impact on the pork industry. The disease syndrome was reported in Europe including Germany, Belgium, the Netherlands, Spain and England. The disease is characterized by reproductive failure, respiratory disease and several clinical signs including loss of appetite, fever, dyspnea, and mild neurological signs. A major component of the syndrome is reproductive failure that manifests itself as premature births, late stage abortions, REF .: 192733 pigs that are born weak, births failed, births with dead product, mummified fetuses, birth rates decreased and return delayed estrus. The clinical signs of respiratory disease are more pronounced in pigs less than three weeks of age, but it is reported to occur in pigs of all stages of production. Affected piglets grow slowly, have rough coats, respiratory distension ("tachycardia") and increased mortality. The disease syndrome has been referred to by many different terms including mysterious pig disease (MSD), porcine epidemic respiratory and abortion syndrome (PEARS), porcine respiratory and infertility syndrome (SIRS). The name now commonly used is porcine reproductive and respiratory syndrome (PRRS); this term will be used throughout this patent application. PRRSV grows preferably in alveolar lung macrophages (Ensvoort et al., 1991). Few cell lines, such as CL2621 and other cloned cell lines from monkey kidney cell line MA-104 are also susceptible to the virus. Some well-known PRRSV strains are known with the CNCM registration numbers I-1102, 1-1140, 1-1387, 1-1388, ECACC V93070108 or ATCC VR 2332, VR 2385, VR 2386, VR 2429, VR 2474 and VR 2402. The PRRSV genome is 15 kb long and contains genes that encode for RNA-dependent RNA polymerase (ORFla and ORFlb) and genes coding for structural proteins (ORFs 2 to 7, Meulenberg et al., 1993 and Meulenberg et al., 1996). 0RF5 codes for the major capsid glycoprotein, designated GP5. The ORFs 2, 3 and 4 code for glycoproteins designated GP2, GP3 and GP4, respectively. These glycoproteins are less abundantly present in purified virions of the Lelystad virus isolate of PRRSV. The GP5 protein is approximately 200 amino acids long and has a molecular weight of 25 kDa and forms a disulfide-linked heterodimer with the M-matrix protein encoded by ORFβ in the ER. The M protein is approximately 190 amino acids long, weighs 19 kDa and is not glycosylated. Nucleocapsid protein N is encoded by ORF7. The analysis of the genomic sequence of PRRSV isolates from Europe and North America, and their reactivity with monoclonal antibodies has proven that they represent two different antigenic types. The isolates from these continents are genetically distinct and must have diverged from a common ancestor relatively several years ago (Murta ugh et al., 1995). The genomic organization of arterivirus simulates coronaviruses and toroviruses in that their replication includes the formation of a nested 3 '-coterminal array of subgenomic mRNA molecules (sg mRNA molecules) (Chen et al., 1993, J. Gen. Virol. 74: 643-660; Den Boon et al., 1990 J. Virol., 65: 2910-2920; De Vries et al., 1990, Nucleic acids Res., 18: 3241-3247; Kuo et al., 1991, J. Virol., 65: 5118-5123; Kuo et al., 1992; application of E.U.A. Serial No. 08 / 131-625 and 08 / 301,435). Partial sequences of several North American isolates have also been determined (U.S. applications Nos. 08 / 131,625 and 08 / 301,435; Mardassi et al., 1994, J. Gen. Virol., 75: 681-685). Vaccines currently available either do not induce viral neutralizing VN antibodies or induce them at inadequate levels necessary for protection against PRRSV infection. Currently there are no commercially available products that contain antibodies for the prevention of PRRSV infection or the treatment of PRRS. Commercial vaccines currently available do not provide adequate protection against PRRS. Conservative calculations indicate that PRRS costs the US industry $ 600 million dollars per year. For these and other reasons, there is a need for the present invention.

BRIEF DESCRIPTION OF THE INVENTION The present inventors are the first to recognize a protective antigenic determinant (PAD) for porcine reproductive and respiratory syndrome virus.

(PRRSV) that provides treatment of and protection against PRRSV infection. Surprisingly, the present inventors have identified that glycoprotein 5 (GP5), matrix protein (M) or a heterodimer of GP5 protein and PRRSV M linked by a disulfide bond gives rise to a PAD that provides protection against PRRSV infections. . The disulfide bond connecting the M protein with the GP5 protein results from an amino acid cysteine in the M protein at position 9 in the North American strains and in position 8 in the European PRRSV strains, and a cysteine amino acid from the GP5 protein located in position 48 of the North American PRRSV strains and in position 50 of the European PRRSV strains. In one embodiment, the invention provides one or more isolated polypeptides comprising an antigenic sequence comprising protein 5 (GP5) of porcine reproductive respiratory syndrome virus (PRRSV), wherein the GP5 protein has variable N-glycosylation patterns of amino acids asparagine located at positions 1-44 of the GP5 protein in the North American PRRSV strains or positions 1-46 of the GP5 protein in the European PRRSV strains. In yet another embodiment, the invention provides an isolated polypeptide comprising an antigenic sequence comprising porcine reproductive and respiratory syndrome virus (PRRSV) matrix (M) protein. In other embodiment, the antigenic sequence includes the GP5 sequence as described above and a PRRSV matrix protein (protein M), wherein the GP5 protein is linked to the M protein by a disulfide bond, which results from an amino acid cysteine in the M protein in position 9 in the North American PRRSV strains and in position 8 in the European PRRSV strains and a cysteine amino acid located at position 48 of the GP5 protein in the North American PRRSV strains or of a cysteine amino acid located in the position 50 in the European PRRSV strains so a heterodimer of GP5-M is produced. In one aspect of the invention, the PAD includes a GP5-M heterodimer comprising the ectodomain of GP5 and the ectodomain of M. In yet another embodiment, the invention provides an isolated nucleic acid encoding any of the PAD polypeptides of the present invention. invention. Accordingly, the invention provides methods for generating antibodies against one or more protective antigenic determinants (PADs) of PRRSV, for preparing a vaccine against at least one PRRSV PAD, for vaccinating pigs, for preventing or treating a PRRSV infection in a pig and to detect antibodies against at least one protective antigenic determinant (PAD) of PRRSV in an animal. The present inventors contemplate a method for generating antibodies against at least one determinant protective antigen (PAD) of PRRSV comprising providing at least one PAD polypeptide or nucleic acid encoding a PAD polypeptide and administering the peptide or nucleic acid to an animal subject. Also described herein is a method for generating antibodies against at least one protective antigenic determinant (PAD) of PRRSV, comprising: providing a PAD polypeptide or a nucleic acid encoding a PAD polypeptide and administering the peptide or nucleic acid to an animal subject. The invention also provides a method for preparing a vaccine against at least one PAD of PRRSV that includes a PAD polypeptide or a nucleic acid encoding a PAD polypeptide. In another embodiment, a method for vaccinating pigs includes administering to a pig the vaccine that includes at least one PAD polypeptide or a nucleic acid encoding a PAD administered to a susceptible pig. The present inventors contemplate a method to prevent or treat a PRRSV infection in a pig, which comprises administering to a pig a therapeutically effective amount of a vaccine having at least one PAD polypeptide or a nucleic acid encoding at least one PAD polypeptide. Yet another method of treating PRRSV infections in a pig comprises administering an antibody against at least one protective antigenic determinant (PAD) of PRRSV to an animal in need of treatment. There is also a method to detect antibodies against at least one protective antigenic determinant (PAD) of PRRSV in an animal. This method includes incubating a biological sample, and including antiserum, from an animal, for example a pig, with a PAD polypeptide for a sufficient time for antibody binding to occur and determining the binding of the antibody to the polypeptide. In another embodiment, the invention provides an isolated antibody directed against at least one PAD polypeptide or a nucleic acid encoding a PAD polypeptide. The invention also discloses a vaccine for protecting against PRRSV infection comprising administering at least one PAD polypeptide or a nucleic acid encoding at least one PAD polypeptide in an amount effective to protect against PRRSV infection. In another aspect, the vaccine also includes a physiologically acceptable vehicle. In yet another embodiment, the invention provides a kit comprising at least one of the following: a PAD polypeptide, a nucleic acid encoding a PAD polypeptide, an antibody directed against a PAD polypeptide or a vaccine that includes a PAD polypeptide or a nucleic acid encoding a PAD polypeptide. Accordingly, an object of the present invention is to provide an isolated polypeptide that includes a PRRSV PAD that includes the PRRSV GP5. An objective of the present invention is to provide an isolated polypeptide comprising a PRRSV PAD that includes the PRRSV matrix (M) protein. A still further objective of the present invention is to provide an isolated polypeptide comprising a PRRSV PAD including the PRRSV GP linked by a disulfide bond to the M protein of PRRSV. Still another objective of the present invention is to provide an isolated nucleic acid encoding a PAD polypeptide. Another objective of the present invention is to provide a method for generating antibodies against a protective antigenic determinant (PAD) of PRRSV. A further object of the present invention is to provide a method for preparing a vaccine. Another objective of the present invention is to provide a method for vaccinating pigs against effective PRRSV PAD to protect pigs against PRRSV infections. An objective of the present invention is to provide a PRRSV PAD vaccine capable of protecting pigs against PRRSV infections. A further object of the present invention is to provide a method for treating or preventing an infection by PRRSV in a pig. Yet another objective of the present invention is to provide a method for detecting antibodies against a protective antigenic determinant (PAD) of PRRSV in an animal. A further object of the present invention is to provide an antibody that immunologically binds a PAD polypeptide of PRRSV. Yet another objective of the present invention is to provide an effective vaccine to protect against PRRSV infection. A further object of the present invention is to provide a diagnostic kit for testing or detecting PRRSV PAD antibodies. These and other embodiments of the invention will become apparent after reference to the following detailed description. All references described herein are incorporated herein by reference in their totalities as if each were incorporated individually.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows the amino acid comparison of the signal sequence GP5 and ectodomain (amino acids 1-60) of PRRSV. The neutralizing epitope of GP5 is underlined. The N-glycosylation sites are in bold. The presence or Location of N-glucans in the ectodomain may be related to susceptibility to or development of neutralizing PRRSV antibodies. Figure 2 shows an unreduced Western immunosorbent assay comparing antisera VR2332 and HLV013. Pigs were immunized with either VR2332 or HLV013 on day 1. All pigs were attacked with VR2332 on day 90. The concentration of proteins was the same for both tested antigens. The antisera were diluted 1: 4000. Row 1 is a standard staircase. Row 2 is antigen IA97-7895 and normal pig serum. Row 3 is HLV013 antigen and normal pig serum. Row 4 is antigen IA97-7895 and antiserum HLV013 42 days after inoculation (p.i.). Row 5 is antigen HLV013 and antiserum HLV013 42 days p.i. Row 6 is antigen IA97-7895 and antiserum VR2332 42 days p.i. Row 7 is antigen HLV013 and antiserum VR2332 42 days p.i. Row 8 is antigen IA97-7895 and antiserum HLV013 104 days p.i. Row 9 is antigen HLV013 and antiserum HLV013 104 days p.i. Row 10 is antigen IA97-7895 and antiserum VR2332 104 days p.i. Row 11 is antigen HLV013 and antiserum VR2332 104 days p.i. Row 12 is a standard ladder. Figure 3 shows an unreduced western blot of different pig serum samples after live PRRSV inoculation. With increased antibody titers neutralizing (FFN), so does the intensity of antibody reaction to the GP-M heterodimer indicating the protective role of specific antibodies for GP-M. The intensity of the antibody reaction to the GP monomer however decreases. A very slight increase in the reaction density can also be seen for the N-N homodimer and the matrix monomer, however previous studies have shown that antibodies specific for these proteins are not protective. Row 1 - ladder, row 2 - title neut = 256, row 3 - title neut = 1024, row 4 - title neut = 2048. Figure 4 shows the response of neutralizing antibodies in pigs that were given either two inoculations of HLV013 or VR2332. Geometric mean titres of 6 pigs per group. The * group 1 (control) pigs remained negative for neutralizing antibodies throughout the study. Compared to group 2 pigs, group 3 pigs had a faster and more robust neutralizing antibody initiation for homologous and heterologous viruses. Figure 5 shows neutralizing antibody responses after inoculation with a heterologous strain (MN184). Please refer to example 2 for a description of the individual rows. This test provides evidence that there is a large difference between Protective antibody responses to strains that differ in glycosylation. Glucans lacking HLV013 before amino acid 44 had a faster and more robust antibody response before the attack with higher cross-activity when compared to VR2332. The post-attack pigs inoculated with HLV013 had a faster anamnestic response and a faster response time to generate antibodies against the attack strain. Note that the GP5-M heterodimer of MN184 and VR2332 is slightly higher (kDa) due to the presence of additional N-glucans. Figure 6 shows the comparison of neutral geometric neutralizing antibody titers generated in Example 3 against different groups of PRRSV glycans. Figure 7 shows the unreduced western blot comparing the antibody reactivity of pigs of groups 1 and 2. See the table in example 3 for a description of the contents of the rows. This figure shows that the increase in protective antibodies generated in the scheme of HLV013-HLV093 compared to HLV013 is only due to an increased reactivity to the GP5-M heterodimer. Figure 8 shows an unreduced western blot comparing antibody profiles of pigs inoculated with HLV013-HLV093 (row 1) to an inoculated pig VR2332-VR2332 (row 3). A ladder is shown in row 2. The protein Purified VR2332 was used with the test antigen (10 ug per row). The dilution of primary antibody was 1: 100 and the secondary dilution was 1: 2000. The titer of anti-VR2332 FFN in row 1 was 256 and in row 3 it was 16. In this way the pigs inoculated with HVL013-HLV093 developed a higher anti-VR2332 neutralizing titer than pigs inoculated with VR2332-VR2332 itself. A clear difference in the reaction to the GP-M heterodimer is also observed in the western blot. Figure 9 shows the GP5-M heterodimer of VR2332. Dotted lines indicate N-linked glycans (not to scale). Figure 10: GP5-M heterodimer of HLV013. Figure 11: GP5-M heterodimer of HLV093. 'Figure 12: GP5-M heterodimer of HLV092. Figure 13: Lelystad GP5-M heterodimer. Figure 14 shows peptide ELISA data.

The peptide ELISA detects antibodies against the neutralizing epitope of PRRSV GP5 virus. Pigs (n = 6 per group) were inoculated with equal titers of either HLV013 or PRRSV VR2332 on day 0. Figure 15 shows the average IDEXX ELISA response in pigs inoculated with either crude viral antigen (CVA) HLV013 or Intervet exterminated vaccine. Figure 16 shows a neutralizing epitope without block or shield of glucans. Figure 17 shows a neutralizing epitope with glucan block (BNE). Figure 18 shows a neutralizing epitope with glucan shield only. Figure 19 shows a highly glycosylated strain with glucan block and glucan shield. Figure 20 shows the complete ORF 5 and 6 of HLV013, which correspond to protein GP5 and M, respectively. Figures 21A and 21B show ORF6 sequences that code for the matrix protein. Figures 22A and 22B show examples of amino acid sequences of signal sequences GP5 and ectodomain of PRRSV. Figure 23 shows the complete ORF 5 of HLV092 corresponding to GP5. Figure 24 shows the complete ORF 5 of HLV093 corresponding to GP5.

DETAILED DESCRIPTION OF THE INVENTION The present inventors are the first to identify a protective antigenic determinant (PAD) for porcine reproductive and respiratory syndrome virus.

(PRRSV) that provides treatment of and protection against PRRSV infection.

It is known that there is reduced or non-heterologous protection with PRRSV vaccines. The present inventors propose that changes in the N-glycosylation patterns of asparagine in the ectodomain of glycoprotein 5 (GP5) of PRRSV or changes in the conformation of GP5 from interactions with another protein, for example, the M protein of PRRSV, play an important role in providing protection against PRRSV. In one aspect, the structure of GP5 is altered by forming a heterodimer with the M protein of PRRSV. See figures 9-12. These changes in nucleotide or amino acid sequences may result in a conformational change or in the addition of subtraction of N-linked glycosylation sites in the GP5 ectodomain. The present inventors also contemplate that changes in the PRRSV M protein may also affect the conformation of the heterodimer. The present inventors believe that changes in the N-glycosylation patterns of asparagine in the ectodomain of glycoprotein 5 (GP5) of PRRSV or a GP5-M heterodimer of glycoprotein 5 (GP5) and a matrix protein (M protein) of PRRSV bound by a disulfide bond gives rise to a PAD that provides protection against PRRSV infections. The disulfide bond connecting the M protein with the GP5 protein results from a cysteine amino acid located in the GP5 protein at position 48 for North American strains and at position 50 for strains European In one aspect, cysteine is located in position 9 of the M protein in North American PRRSV strains and in position 8 in European PRRSV strains. In one embodiment, the invention provides one or more PADs that include isolated polypeptides comprising an antigenic sequence comprising PRRSV glycoprotein 5 (GP5), wherein the GP5 protein has varying N-glycosylation patterns of asparagine amino acids located at positions 1 -44 of the GP5 protein in North American PRRSV strains or positions 1-46 of the GP5 protein in the European PRRSV strains. In one aspect, the PAD includes the GP5 ectodomain. In another aspect, the PAD includes the neutralizing epitope of the GP5 ectodomain. In one aspect, the neutralizing epitope has an amino acid sequence of SHLQLIYNL. In yet another embodiment, the invention provides a PAD that includes an isolated polypeptide comprising an antigenic sequence comprising matrix protein (M) PRRSV. In one aspect, the antigenic sequence is the ectodomain of the M protein. In one aspect, the ectodomain includes the first 30 amino acids or less of the M protein of the North American or European PRRSV strains. In another embodiment, the antigenic sequence includes the GP5 sequence as described herein and a PRRSV matrix protein (protein M) as described in present, wherein the GP5 protein is linked to the M protein by a disulfide bond, which results from a cysteine amino acid of the M protein in position 9 in the North American PRRSV strains and in the 8 position in the European and a amino acid cysteine located at position 48 of the GP5 protein in North American PRRSV strains or of a cysteine amino acid located at position 50 in the European PRRSV strains so that a GP5-M heterodimer is produced. In one embodiment of the invention, a PAD of GP5 may not have glucans of amino acids 1-35 in the GP5 protein of NA PRRSV. In another aspect, a PAD of GP5 can have a glucan at position 44 in the GP5 protein of NA PRRSV. In another aspect, a PAD of GP5 may have a glucan at position 44 in GP5 of NA PRRSV and have glucans present or absent in amino acids 1-35 in the GP5 protein of NA PRRSV, for example, as found in some strains NA PRRSV. In one embodiment of the invention, a PAD heterodimer of GP5-M may not have glucans of amino acids 1-35 in the GP5 protein of NA PRRSV. In another aspect, a GP5-M heterodimer PAD can have a glucan at position 44 in the GP5 protein of NA PRRSV. In another aspect, a PAD of the GP5-M heterodimer can have a glucan at position 44 in the GP5 of NA PRRSV and have glycans present or absent in amino acids 1-35 in the GP5 protein of NA PRRSV, by example, as found in some strains of NA PRRSV. In one embodiment of the invention, a GP5 DBP can also not have glycans of amino acids 1-37 in the GP5 protein of PRRSV, as found in Lelystad. In another aspect, a PAD of GP5 can have a glucan in opposition 46 in the GP5 protein of European PRRSV. In another aspect, a GP5 PAD can have a glucan at position 46 in GP5 of European PRRSV and have glycans present or absent in amino acids 1-37 in the GP5 protein of European PRRSV, for example, as found in some European PRRSV strains. In one embodiment of the invention, a PAD of the GP5-M heterodimer may not have glucans of amino acids 1-37 in the GP5 protein of European PRRSV, as found in Lelystad. In another aspect, a PAD of the GP5-M heterodimer can have a glucan at position 46 in the GP5 protein of European PRRSV. In another aspect, a PAD of the GP5-M heterodimer can have a glucan at position 46 in GP5 of European PRRSV and have glycans present or absent in amino acids 1-37 in the GP5 protein of European PRRSV, for example, as found in some strains of European PRRSV. In another embodiment, the PAD includes an antigenic sequence comprising amino acids 36-45 of GP5 of NA PRRSV and the ectodomain of the M protein of PRRSV. In other appearance, the ectodomain of the M protein includes amino acids 1-30. In another embodiment of the invention, the PAD includes an antigenic sequence comprising amino acids 38-47 of GP5 of EU PRRSV and the ectodomain of the M protein of PRRSV. The GP protein may have varying N-glycosylation patterns of asparagine amino acids located at positions 1-44 of the GP5 protein in North American PRRSV strains or positions 1-46 of the GP5 protein in European PRRSV strains. These variations are also included in PAD of the invention. Thus, with the identification of a PAD comprising a GP5 protein that is N-glycosylated or non-N-glycosylated amino acids 1-46 of GP5 electrodominio or an M protein or a GP5-M heterodimer of a M protein linked by disulfide to a GP5 protein that is N-glycosylated or non-N-glycosylated from amino acids 1-46 of the GP5 ectodomain of PRRSV, it is possible to develop an effective vaccine against PRRSV. A vaccine according to the present invention may include a PAD polypeptide as described herein, and may include but is not limited to immunogenic fragments, derivatives, homologs or variants thereof, comprising an amino acid sequence of at least 65. Identical%, 80% identical, 95% identical or 100% identical to any of the PAD amino acid sequences in the figure 1. SEQ ID NOS: _. The PADs according to the present invention will include derivatives, homologs or variants thereof, which fragments can be easily screened for immunogenic activity, as well as immunogenic fragments, for example, those shown in Figures 1 and 21 (SEQ ID NOS). : _). In this manner, derivatives, homologs or variants thereof can be tested using neutralization assays or tested for the ability of the derivatives, homologs or variants thereof to provide protection against swine attacked with a heterologous PRRSV using assays such as the Fluorescent focus neutralization (FFN) or the Western blot assay for heterodimer can be used to give an indication of heterologous antibody production. Thus, specific fragments may include but are not limited to fragments having amino acid sequences shown in Figures 1 and 21 (SEQ ID NO: _). It is logical to assume that fragments of GP5-M heterodimers can provide similar degrees of protection. In one aspect, the vaccine can be attenuated, inactivated, subunit, recombinant, vector or DNA based. In a further aspect, the vaccines can be used in an immunization scheme or protocol. In another aspect of the invention, a PAD can be used to produce antibodies to diagnose whether a vaccination against PSSRV based on a PAD was successful or to produce vaccines for prophylaxis and / or treatment of PRRSV infections. In addition to use as vaccines, the PAD polypeptides of the present invention can be used as antigens to stimulate the production of antibodies for use in passive immunotherapy, to be used as diagnostic reagents and to be used as reagents in other processes such as affinity chromatography.

Definitions: As used herein, a "porcine reproductive and respiratory syndrome virus" or "PRRSV" refers to a virus that causes the diseases PRRS, PEARS, SIRS, MSD and / or PIP (the term "PIP" appears now be disadvantaged), including the Iowa strain of PRRSV, other strains of PRRSV found in the United States (eg, VR 2332), PRRSV strains found in Canada (eg, IAF-exp91), PRRSV strains found in Europe (for example, Lelystad virus, PRRSV-10), and closely related variants of these viruses which may have appeared and which will appear in the future. An unaffected pig is a pig that has either been exposed to an infectious agent of porcine reproductive and respiratory disease, or which has been exposed to an infectious agent of porcine reproductive and respiratory disease such as PRRSV but does not show symptoms of the disease. disease. An affected pig is one that shows symptoms of PRRS or from which PRRSV can be isolated. The terms "treat" or "treatment", as used herein, refer to the reduction or alleviation of at least one adverse effect or symptom of PRRSV infection. Clinical signs or symptoms of PRRS may include weight loss, reduced weight gain, lethargy, respiratory distress, "tachycardia" (forced expiration), fevers, rough coats, sneezing, coughing, eye edema, and occasionally conjunctivitis. The lesions may include large and / or microscopic lung lesions, myocarditis, lymphadenitis, encephalitis, and rhinitis. In addition, less virulent and non-virulent forms of PRRSV and strain Iowa have been found, which may cause either a subset of the above symptoms or no symptoms at all. The less virulent and non-virulent forms of PRRSV can be used in accordance with the present invention to provide protection against porcine reproductive and respiratory disease, however. As used herein, an "ORF" refers to an open reading frame, or polypeptide coding segment, isolated from a viral genome, including a PRRSV genome. In the present polynucleic acid, an ORF may be included in part (as a fragment) or complete, and may overlap with the 5 'or 3' sequence of an ORF adjacent. "Nucleic acid" or "polynucleotide" as used herein refers to polymers containing purine and pyrimidine of any length, either polyribonucleotides or polydeoxyribonucleotides or mixed polyribo-polydeoxyribonucleotides. This includes single and double-stranded molecules, ie cDNA, mRNA, DNA-DNA, DNA-RNA and RNA-RNA hybrids, as well as "protein nucleic acids" (PNA) formed by conjugating bases to a structure of base of amino acids. This also includes nucleic acids containing modified bases. A "vector" is any means for the transfer of a nucleic acid to a host cell. A vector can be a replicon to which another DNA segment can join to thereby cause replication of the attached segment. A "replicon" is any genetic element (eg, plasmid, phage, cosmic, chromosome, virus) that functions as an autonomous unit of DNA replication in vivo, that is, capable of replication under its own control. The term "vector" includes both viral and non-viral means for introducing the nucleic acid into an in vitro, ex vivo or in vivo cell. Viral vectors include alphaviruses, retroviruses, adeno-associated viruses, pox, baculoviruses, vaccinia, herpes simplex, Epstein-Barr and adenovirus vectors. Non-viral vectors include, but not they are limited to plasmids, liposomes, electrically charged lipids (cytofectins), DNA-protein complexes and biopolymers. In addition to a nucleic acid, a vector may also contain one or more regulatory regions, and / or selectable markers useful for selecting, measuring and monitoring nucleic acid transfer results (transfer to which tissues, duration of expression, etc.). A "cassette" refers to a segment of DNA that can be inserted into a vector at specific restriction sites. The DNA segment codes for a polypeptide of interest, and the cassette and restriction sites are designed to ensure the insertion of the cassette into the proper reading frame for transcription and translation. A cell has been "transfected" by exogenous or heterologous DNA when this DNA has been introduced into the cell. A cell has been "transformed" by exogenous or heterologous DNA when the transfected DNA makes a phenotypic change. Transformation DNA can be integrated (covalently linked) into chromosomal DNA that makes up the genome of the cell. A "nucleic acid molecule" refers to the polymeric form of ribosomal phosphate ester (adenosine, guanosine, uridine or histidine, "RNA molecules") or deoxyribonucleosides (deoxyadenosine, Desociguanosine, deoxythymidine or deoxycytidine; "DNA molecules"), or any phosphoester analogue thereof, such as phosphorothioates and thioesters, either in the form of a single strand, or of a double-stranded helix. The double-stranded DNA-DNA, DNA-RNA and RNA-RNA helices are possible. The term nucleic acid molecule, and in particular DNA or RNA molecule, refers only to the primary and secondary structure of the molecule, and does not limit it to any particular tertiary form. Thus, this term includes double-stranded DNA found, inter alia, in linear or circular DNA molecules (eg, restriction fragments), plasmids and chromosomes. In describing the structure of particular double-stranded DNA molecules, sequences can be described herein in accordance with the normal convention of giving only the sequence in the 5 'to 3' direction along the non-transcribed strand of DNA ( that is, the strand that has a sequence homologous to the mRNA). A "recombinant DNA molecule" is a DNA molecule that has undergone molecular biological manipulation. As used herein, a "polypeptide" generally refers to peptides and proteins having more than eight amino acids. "Conservatively modified variants" applies to both amino acid and nucleic acid sequences. With respect to particular nucleic acid sequences, "Conservatively modified variants" refers to those nucleic acids that encode identical or essentially identical amino acid sequences, or when the nucleic acid does not code for an amino acid sequence, to essentially identical sequences. Due to the degeneracy of the genetic code, a large number of functionally identical nucleic acids code for any suitable polypeptide. For example, the codons CGU, CGC, CGA, CGG, AGA and AGG all code for the amino acid arginine. Thus, in each position in which an arginine is specified by a codon, the codon can be altered to any of the corresponding codons described without altering the encoded polypeptide. These variations of nucleic acid are "silent substitutions" or "silent variations", which are a kind of "conservatively modified variations". Each polynucleotide sequence described herein that codes for a polypeptide also describes all possible silent variations, except where indicated to the contrary. Thus, silent substitutions are an implicit characteristic of each nucleic acid sequence that codes for an amino acid. Someone of ability will recognize that each codon in a nucleic acid (except AUG, which is ordinarily the only codon for methionine) can be modified to produce a functionally identical molecule by standard techniques. In some embodiments, the nucleotide sequences encoding a PAD are preferably optimized for expression in a particular host cell (eg, yeast, mammalian, plant, fungal and the like) used to produce the enzymes. In terms of amino acid sequences, someone of ability will recognize that individual substitutions, deletions or additions to a nucleic acid, peptide, polypeptide or protein sequence that alter, add or delete a single amino acid or a small percentage of amino acids in the encoded sequence is a "conservatively modified variant" referred to herein as a "variant" when the alteration results in the substitution of an amino acid with a chemically similar amino acid. Conservative substitution tables that provide functionally similar amino acids are well known in the art. See, for example, Davis et al., "Basic Methods in Molecular Biology" Appleton & Lange, Norwalk, Connecticut (1994). These conservatively modified variants are in addition to and do not exclude polymorphic variants, homologues between species and alleles of the invention. The following eight groups each contain amino acids that are conservative substitutions of each other: 1) Alanine (A), Glycine (G); Aspartic acid (D), Glutamic acid (E); 3) Asparagine (N), Glutamine (Q); 4) Arginine (R), Lysine (K); 5) Isoleucine (I), Leucine (L), Methionine (M), Valine (V); 6) Phenylalanine (F), tyrosine (Y), Tryptophan (W); 7) Serine (S), Threonine (T) and 8) Cysteine (C), Methionine (M) (see, for example, Creighton, 1984, Proteins). The terms "identical" or "percent identity", in the context of two or more nucleic acid sequences or polypeptides, refer to two or more sequences or subsequences that are the same or have a specified percentage of amino acid residues or nucleotides that are equal (ie, approximately 70% identity, preferably 75%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95 %, 96%, 97%, 98%, 99%, or higher identity over a specified region (eg, the neutralizing epitope sequence of a GP5 protein of PRRSV), when compared and aligned for maximum correspondence over a window of comparison or designated region) as measured using a BLAST or BLAST 2.0 sequence comparison algorithm with preset parameters described below, or by manual alignment or visual inspection. It is then said that these sequences are "substantially identical". This definition also refers to the complement of a test sequence. The definition also includes sequences that have deletions and / or additions, as well as those that have substitutions. As described below, preferred algorithms can compensate for spaces and the like. Preferably, the identity exists over a region that is at least about 25 amino acids or nucleotides long, or most preferably over a region that is 50-100 amino acids or nucleotides long. For sequence comparison, typically a sequence acts as a reference sequence, with which test sequences are compared. When a sequence comparison algorithm is used, test sequences and references are entered into a computer, subsequence coordinates are designed, if necessary, and sequence algorithm program parameters are designed. Preset program parameters can be used, or alternative parameters can be designed. The sequence comparison algorithm then calculates the percentage sequence identities for the test sequences in relation to the reference sequence, based on the program parameters. A "comparison window", as used herein, includes reference to a segment of any of a number of contiguous positions selected from the group consisting of 20 to 600, usually around 50 to about 200, more usually about 100. to about 150 in which a sequence can be compared to a reference sequence of the same number of contiguous positions after the two sequences are optimally aligned. Methods of sequence alignment for comparison are well known in the art. The optimal alignment of sequences for comparison can be carried out, for example, by the local homology algorithm of Smith & Waterman, 1991, Adv .. Appi. Math. 2: 482, by the homology alignment algorithm of Needleman & Wunsch, 1970, J. Mol. Biol. 48: 443, by the Pearson & Lipman, 1988, Proc. Nat'l. Acad. Sci. USA 85: 2444, for the computerized implementations of these algorithms (GAP, BESTFIT, FASTA and TFASTA in the Wisconsin Genetics software package, Genetics Computer Group, 575 Science Dr., Madison, Wis.), Or by manual alignment and visual inspection (see, for example, Current Protocols in Molecular Biology (Ausubel et al., eds., 1995 supplement.) Another example of an algorithm that is suitable for determining percent sequence identity and sequence similarity are BLAST algorithms. and BLAST 2.0, which are described in Altschul et al., 1977, Nuc Acids, Res. 25: 3389-3402 and Altschul et al., 1990, J. Mol. Biol. 215: 403-410, respectively. Software to carry out the BLAST analyzes is publicly available through the National Center for Biotechnology Information (http: // redmundial in ncbi.nlm.nih.gov/). This algorithm includes first identifying several high-score sequences (HSPs) by identifying short words of length W in the query sequence, which either match or satisfy a certain positive value threshold score when they are aligned with a word of equal length in a database sequence. T is referred to as the adjacent word score threshold (Altschul et al., Cited above). This initial adjacent word acts as seeds to initiate searches to find longer HSPs that contain them. Word hits are extended in both directions along each sequence for as long as the cumulative alignment score can be increased. Cumulative scores are calculated using, for nucleotide sequences, the parameters M (reward score for a pair of matching residues, always> 0) and N (penalty score for mismatched residues, always <0). For amino acid sequences, a scoring matrix is used to calculate the cumulative score. The extension of word hits in each direction stops when: the cumulative alignment score falls by the quantity X from its maximum achieved value; the cumulative score goes to 0 or less, due to the accumulation of negative residue residue alignments; or the end of each sequence is reached. The BLAST algorithm parameters W, T and X determine the sensitivity and speed of the alignment. The BLASTN program (for nucleotide sequences) uses as presets a word length (W) of 11, an expectation (E) or 10, M = 5, N = 4 and a comparison of both strands. For amino acid sequences, the BLASTP program uses a word length of 3, and expectation (E) of 10, and the BLOSUM62 scoring matrix (see Henikoff &Henikoff, 1989, Proc. Nati. Acad. Sci. USA) as preset. 89: 10915) alignments (B) or 50, expectation (E) of 10, M = 5, N = 4, and a comparison of both strands. The BLAST algorithm also performs a statistical analysis of the similarity between two sequences (see, for example, Karlin &Altschul, 1993, Proc. Nat'l. Acad. Sci. USA 90: 5873-5787). One measure of similarity provided by the BLAST algorithm is the smallest sum probability (P (N)), which provides an indication of the probability by which a match between two nucleotide or amino acid sequences would occur with opportunity. For example, a nucleic acid is considered similar to a reference sequence if the smallest sum probability in a comparison of the test nucleic acid with the reference nucleic acid is less than about 0.2, most preferably less than about 0.01 and more preferably less than about 0.001.

An indication that two nucleic acid sequences or polypeptides are substantially identical is that the polypeptide encoded by the first nucleic acid is immunologically cross-reactive with the antibodies raised against the polypeptide encoded by the second nucleic acid, as described below. Thus, a polypeptide is typically substantially identical to a second polypeptide, for example, when the two polypeptides differ only by conservative substitutions. Another indication that two nucleic acid sequences are substantially identical is that the two molecules or their complements hybridize to one another under severe conditions, as described below. Yet another indication that two nucleic acid sequences are substantially identical is that the same primers can be used to amplify the sequence. As used herein, a protein or peptide is said to be "isolated" or "purified" when it is substantially free of cellular material or free of chemical precursors or other chemicals. The variant peptides of the present invention can be purified at homogeneity or other degrees of purity. The level of purification will be based on the desired use. The critical characteristic is that the preparation allows the desired function of the variant peptide, even if it is in the presence of considerable from other components. In some uses, "substantially free of cellular material" includes preparations of the variant peptide having less than about 30% (by dry weight) of other proteins (ie, contaminating protein), less than about 20% of other proteins, less than about 10% of other proteins or less than about 5% of other proteins. When the variant peptide is produced recombinantly, it can also be substantially free of the culture medium, ie, the culture medium represents less than about 20% of the volume of the protein preparation. The phrase "substantially free of chemical precursors or other chemicals" includes preparations of the variant peptide in which it is separated from chemical precursors or other chemicals that are involved in its synthesis. In one embodiment, the phrase "substantially free of chemical precursors or other chemicals" includes preparations of the variant protein having less than about 30% (by dry weight) of chemical precursors or other chemicals, less than about 20% of precursors chemicals or other chemicals, less than about 10% chemical precursors or other chemicals, or less than about 5% chemical precursors or other chemicals. Isolated variant proteins can be purified of cells that are naturally expressed, purified from cells that have been altered to express them (recombinants), or synthesized using known protein synthesis methods. For example, a nucleic acid molecule according to the variant PAD protein is cloned into an expression vector, the expression vector is introduced into a host cell and the variant protein is expressed in the host cell. The variant protein can then be isolated from the cells by an appropriate purification scheme using standard protein purification techniques. Many of these techniques are described in detail below. A protein comprises an amino acid sequence when the amino acid sequence is at least part of the final amino acid sequence of the protein. Thus, the protein can be a PAD polypeptide, a variant PAD polypeptide and / or have additional amino acid molecules, such as amino acid residues (contiguous coding sequence) that are naturally associated with this or amino acid residues / heterologous peptide sequence. . This protein may have few additional amino acid residues and may comprise several hundred or more additional amino acids. A brief description of how various types of these proteins can be made / isolated is given below.

The variant proteins of the present invention can be linked to heterologous sequences to form chimeric or fusion proteins. These chimeric and function proteins comprise a variant protein operably linked to a heterologous protein having an amino acid sequence not substantially homologous to the variant protein. "Operably linked" indicates that the variant protein and the heterologous protein are fused in frame. The heterologous protein can be fused to the N-terminus or C-terminus of the variant protein. A chimeric or fusion protein can be produced by standard recombinant DNA techniques. For example, DNA fragments that code for the different protein sequences are ligands together in frame according to conventional techniques. In another embodiment, the fusion gene can be synthesized by conventional techniques including automated DNA synthesizers. Alternatively, a PCR amplification of gene fragments can be carried out using anchor primers that give rise to complementary overhangs between two consecutive gene fragments which can be subsequently fixed and reamplified to generate a chimeric gene sequence (see Ausubel et al., Current Protocols in Molecular Biology, 1992). Moreover, many expression vectors are commercially available that already encode a fusion portion (eg, a GST protein). A variant protein coding nucleic acid can be cloned into this expression vector such that the fusion protein is linked to the variant protein in frame. Polypeptides sometimes contain amino acids that are not the 20 amino acids commonly known as the 20 naturally occurring amino acids. In addition, many amino acids, including terminal amino acids, can be modified by natural processes, such as processing and other modifications after translation, or by chemical modification techniques well known in the art. Common modifications that occur naturally in polypeptides are described in basic texts, detailed monographs and research literature, and are well known to those skilled in the art. Accordingly, the variant peptides of the present invention also encompass derivatives or analogs in which a substituted amino acid residue is not encoded by the genetic code, in which a substituent group is included, in which a mature polypeptide is fused to another compound, such as a compound for increasing the half-life of the polypeptide (eg, polyethylene glycol), or in which additional amino acids are fused to the mature polypeptide, such as a leader or secretory sequence or a sequence for the purification of the mature polypeptide or a sequence of proproteins. Known modifications include, but are not limited to, acetylation, acylation, ADP-ribosylation, amidation, covalent attachment of flavin, covalent attachment of a heme moiety, covalent attachment of a nucleotide or nucleotide derivative, covalent attachment of a lipid or derivative of lipid, covalent fixing of phosphotidylinositol, crosslinking cyclization, formation of disulfide bonds, demethylation, formation of covalent entanglements, formation of cystine, formation of pyroglutamate, formylation, gamma-carboxylation, glycosylation, formation of GPI anchors, hydroxylation, iodination, methylation , myristoylation, oxidation, proteolytic processing, phosphorylation, prenylation, racemization, selenoylation, sulfation, RNA-mediated addition of amino acid transfer to proteins such as arginilation and ubiquitination. The present invention further provides fragments of the variant proteins of the present invention, in addition to proteins and peptides comprising and consisting of these fragments, so long as these fragments act as an antigenic determinant and / or provide treatment of and / or protection against infections by PRRSV such as provided in the present invention. As used herein, a fragment comprises at least 8 or more contiguous amino acid residues of a PAD polypeptide or variant protein. The terms "fragment", "derivative" and "homologous" when referring to the polypeptides according to the present invention means a polypeptide that retains essentially the same function or biological activity as the aforementioned polypeptide, ie acts as a determinant antigenic and / or provides treatment and / or protection against PRRSV infections. These fragments, derivatives and homologs may be selected based on the ability to preserve one or more of the biological activities of a PAD polypeptide, ie, act as an antigenic determinant and / or provide treatment of and / or protection against PRRSV infections. Thus, a homologue includes a polypeptide from a different strain or genus that retains essentially the same function or biological activity as the PAD polypeptide. The polypeptide vaccines of the present invention can be recombinant polypeptides, natural polypeptides or synthetic polypeptides, preferably recombinant polypeptides. An "antigenic determinant" is, unless otherwise indicated, a molecule that is capable of developing an immune response in an animal or species particular. Antigenic determinants include proteinaceous molecules, ie, polyamino acid sequences, polypeptides, fragments, derivatives or variants which may include other portions, for example, carbohydrate moieties, such as glucans and / or lipid portions. The antigenic determinants of the present invention can also be heterologous, including antigenic determinants of neutralizing epitopes of other viruses, strains or PRRSV family, which cross-react with an antibody or antiserum produced in response to a PAD of the present invention, by example, GP5-M heterodimers, and all are capable of developing an immune response in a particular animal, such as a pig. "M" as used herein refers to a PRRSV matrix or polypeptide protein. The term "M" as used herein also includes fragments, derivatives or homologs thereof that can form a heterodimer with a GP5 protein and provide cross-reactivity with PRRSV strains. "GP5" as used herein refers to a PRRSV glycoprotein. The term "GP5" as used herein also includes fragments, derivatives or homologs thereof that can form a heterodimer with an M protein and provide cross-reactivity with PRRSV strains. Thus, a GP5 homologue, for example, from another virus arterivirus, is contemplated as part of the invention. The position in the GP analogue corresponding to position 44 of GP5 in NA PRRSV strains or to position 46 of GP5 in EU PRRSV strains can be determined by someone of ordinary skill in the art and also included as part of the invention. The term "GP-M heterodimer" as used herein also includes a GP5 protein associated with the PRRSV M protein or any other protein or peptide that alters the conformation of GP5 in such a way that when administered to a pig provides protection against PRRSV. One skilled in the art would be able to test changes in GP5 conformation using standard techniques and methods, for example, using a monoclonal antibody that only recognizes the GP5 protein when it is not in heterodimeric form. Thus, one aspect of the invention includes GP5 or M proteins of the same or different strains or viruses, including but not limited to equine arteritis virus (EAV), lactate dehydrogenase (LDV) elevation and virus of the simian hemorrhagic fever (SHFV). Therefore, according to the invention, the chimeric GP5-M heterodimers can be used as PAD, for example, for use in immunization protocols. As used herein, the ectodomain of the GP5 protein is approximately 60-65 amino acids long and includes a signal peptide and post-processing of a short N-terminal region of about 30 amino acids long which may include N-glycosylation sites. See figure 1. As used herein, the term "hypervariable region" refers to a region of the ectodomain of the GP5 protein, eg, amino acids 1 to 35 of GP5 in North American strains (NA) of PRRSV and amino acids 1 to 37 of GP5 in strains of European-type PRRSV (EU) or of a homolog of GP5 or its equivalent. The corresponding regions and positions of the ectodomain in other fragments, homologs or derivatives of GP5 can be determined for example by alignment and used in the present invention. Also, mutations of one or more amino acids in the GP5 ectodomain that result in the glycosylation of that amino acid are contemplated as part of the invention. In this way, it could be possible to generate a GP5 that had a glycosylation in the ectodomain in a position that was not 44 in NA PRRSV strains or 46 in strains of EU PRRSV that have the same effect (protection against PRRSV infection). These variants can also be used in the present invention. As used herein, the ectodomain of the M protein refers to the first 30 amino acids of the N-terminus of the M protein or of a homologue or equivalent thereof. The corresponding regions and positions of the Ectodomain in other fragments, homologs or M protein derivatives can be determined for example by alignment and used in the present invention. The phrase "biological sample" refers to a fluid or tissue of a mammal (e.g., a pig, rabbit or horse) that commonly contains antibodies or viral particles. These components are known in the art and include, without limitation, blood, plasma, serum, spinal fluid, lymphatic fluid, secretions from the respiratory, intestinal or genitourinary tracts, tears, saliva, milk, white blood cells and myelomas. As used herein, an antibody is defined in terms consistent with those recognized within the art: they are proteins of various subunits produced by a mammalian organism in response to an antigenic attack. Antibodies of the present invention include monoclonal antibodies and polyclonal antibodies, as well as fragments of these antibodies, including, but not limited to, Fab or F (ab ') hd 2 fragments, and Fv. As used herein, the term "subunit" refers to a portion of PRRSV that is in turn antigenic, that is, capable of inducing an immune response in an animal. The term should be considered to include subunits that are obtained by both recombinant and biochemical methods. As used herein, the term "multivalent" means a vaccine that contains one or more of the PRRSV isolate, either of the same species (ie, different PRRSV isolates) or of a different PRRSV. Even for a given genus and species of PRRSV, each isolate may share some antigens with other isolates (ie, "common" antigens), although other antigens will be unique to that isolate. Because a multivalent vaccine provides a wider variety of antigens to the host immune system, the immune response stimulated in the host is broader than that stimulated only by an individual isolate. As used herein, the term "isolated" refers to a virus obtained from a specific source. Isolated is used interchangeably with the term "strain". As used herein, the term "virulent" means an isolate that retains its ability to be infectious in a host animal. As used herein, the term "inactivated" means a vaccine that contains an infectious organism that is no longer capable of replication and / or growth. As used herein, the term "PRRSV" refers to all viruses belonging to the PRRSV species in the genus Arterivirus within the family rtrteriviridae. As used herein, the term "vaccine" as used herein refers to a composition Pharmaceutical comprising at least one immunologically PAD that induces an immune response in an animal and possibly, but not necessarily, one or more additional components that increase the immunological activity of the aforementioned active component. A vaccine may further comprise typical additional components for pharmaceutical compositions. The immunologically active component of a vaccine may comprise whole live virus either in its original form or as an attenuated virus in a so-called modified live vaccine or inactivated virus by suitable methods in a so-called killed vaccine. In another form, the immunologically active component of a vaccine may comprise suitable elements of the viruses (subunit vaccines) with which these elements are generated either by destroying the whole organism or the growth cultures of these viruses and subsequent purification steps. which are produced in the desired structures, or by synthetic processes induced by a suitable manipulation of a suitable system such as, but not restricted to, bacteria, insects, mammals or other species, further isolation and purification procedures subsequent or by the induction of synthetic processes in the animal that requires a vaccine by direct incorporation of genetic material using suitable pharmaceutical compositions (vaccination with polynucleotides). A vaccine can comprise one or simultaneously more than one of the elements described above. The terms "protect", "protection", "protective immunity" or "protective immune response", as used herein, are intended to mean that the pig or host mounts an active immune response to the vaccine or polypeptides of the present invention, in such a way that after a subsequent exposure to the virus or a virulent viral attack, the pig is able to fight the infection. 'Thus, a protective immune response would reduce the incidence of morbidity and mortality from subsequent exposure to the virus among the host pigs. It will be understood by those skilled in the art that in a commercial pig scenario, the production of a protective immune response can be assessed by evaluating the effects of vaccination on the herd as a whole, for example, there may still be morbidity and mortality in a minority of pigs vaccinated. In addition, protection also includes a reduction in the severity of any large or histopathological changes (eg, lesions in the lung) and / or symptoms of PPRS disease, as compared to those attacks or symptoms typically caused by the isolate in pigs. similar ones which are not protected (that is, in relation to adequate control). Thus, a protective immune response will reduce the symptoms of PRRSV, including but not limited to a reduction in the signs of clinical symptoms of PRRS that they include weight loss, reduced weight gain, lethargy, respiratory distress, "tachycardia" (forced expiration), fevers, rough coats, sneezing, cough, ocular edema, conjunctivitis, microscopic lung lesions due to large lesions, myocarditis, lymphadenitis, encephalitis and rhinitis compared to the control pig. As used herein, the term "live virus" refers to a virus that retains the ability to infect an appropriate subject (as opposed to inactivated (killed) or subunit vaccines). As used herein, "immunologically effective amount" refers to an amount, which is effective to reduce, eliminate, treat, prevent or control the symptoms of infections, diseases, disorders or conditions caused by PRRSV. In one embodiment, the present invention relates to a polypeptide comprising a PAD of PRRSV, hereinafter referred to as a PAD polypeptide. The present inventors contemplate that the polypeptide may be a homolog, a derivative or a variant of the PAD, or an immunologically active or functional fragment thereof. The polypeptide can be isolated, synthesized or expressed recombinantly using the PAD coding nucleic acids described herein. Examples of PADs of the present invention include but are not limited to the amino acid sequences shown in Figures 1, 20, 21 and 22 (SEQ ID NOS: _). These PADs can be administered as fragments, polypeptides, proteins or as a PRRSV having the desired glycosylation of the ectodomain of the GP5-M heterodimer according to the immunization protocols described herein. Additional examples of nucleic acid molecules of the present invention include, but are not limited to, the polynucleotide sequences encoding the polypeptide of (HLV013) MLGRCLTAGC CSQLPFLWCI VPFCLVALVN ANSNSGSHLQ LIYNLTLCEL NGTDWLKDKF (SEQ ID NO: _) or the polypeptide of and HLV093 MLGRCLTACY CLRLLSLWCI VPFWFAVLVS ANSNSSSHLQ SIYKLTLCEL NGTEWLNERF (SEQ ID NO: _). The present invention also provides isolated and / or recombinant nucleic acids encoding a PAD polypeptide of the invention. In accordance with one embodiment of the invention, the PAD nucleotide sequence encodes a PRRS-neutralizing epitope. Furthermore, it should be understood based on the general state of the art that other sequences equivalent to the nucleotide or amino acid sequences of the PADs are covered by the present invention. For example, some deletions, insertions and substitutions in the amino acid sequence of the GP5 ectodomain are covered by the present invention, unless this mutation arrests the ability of PAD to induce generation of neutralizing antibodies. The PAD coding nucleic acids according to the invention are useful for several purposes, including the recombinant expression of the corresponding PAD polypeptides. The nucleic acids of the invention include those that code for a complete PAD as well as those that code for a subsequence of a PAD polypeptide. For example, the invention includes nucleic acids encoding a polypeptide that is not a full-length PAD, but nonetheless has protective antigenic activity against PRRSV infection. The invention includes not only nucleic acids that include the nucleotide sequences shown herein, but also nucleic acids that are substantially identical to, or substantially complementary to, the embodiments exemplified. For example, the invention includes nucleic acids that include a nucleotide sequence that is at least about 70% identical to one that is shown herein, most preferably at least 75%, even more preferably at least 80%, more preferably at least 85%, still more preferably at least 90% and most preferably at least about 95% identical to an exemplified nucleotide sequence. The nucleotide sequence can be modified as described above, as long as the encoded polypeptide is capable of inducing the generation of neutralizing antibodies. The nucleic acids encoding a PAD polypeptide of the invention can be obtained using methods that are known to those skilled in the art. Suitable nucleic acids (eg, cDNA, genomic or subsequent) can be cloned, or amplified by in vitro methods such as polymerase chain reaction (PCR) using appropriate primers, the ligase chain reaction (LCR) , the transcription based amplification system (TAS), the self-sustained sequence replication (SSR) system. A wide variety of cloning and amplification methodologies in vi tro are well known by trained people. Examples of these techniques and sufficient instructions to direct people of ability through many of the cloning exercises are found in Berger and Kimmel, Guide to Molecular Cloning Techniques, Methods in Enzymology 152 Academic Press, Inc., San Diego, California ( Berger); Sambrook et al. (1989) Molecular Cloning-A Labora tory Manual (2nd ed.), Vol. 1-3, Cold Spring Harbor Laboratory, Cold Spring Harbor Press, NY (Sambrook et al.); Curren t Protocols in Molecular Biology, F.

M. Ausubel et al., Eds., Current Protocols, a merger between Greene Publishing Associates, Inc. and John Wiley & Sons, Inc., (Supplement 1994) (Ausubel); Cashion et al., Patent of E.U.A. No. 5,017,478 and Carr, European Patent No. 0,246,864. Examples of techniques sufficient to direct people of ability through an amplification method in vi tro are found in Berger, Sambrook and Ausubel, as well as in Mullis et al., (1987) patent of E.U.A. No. 4,683,202; PCR Protocols A Guide to Methods and Applications (Innis et al., Eds.) Academia Press Inc. San Diego, Calif. (1990) (Innis); Amheim & Levinson (October 1, 1990) C & EN 36-47; The Journal of NIH Research (1991) 3: 81-94; (Kwoh et al. (1989) Proc. Na ti. Acad. Sci. USA 86: 1173; Guatelli et al. (1990) Proc. Na ti. Acad. Sci. USA 87, 1874; Lomell et al. (1989) J. Clin. Chem., 35: 1826; Landegren et al., (1988) Science 241: 1077-1080; Van Brunt (1990) Biotechnology 8: 291-294; Wu and Wallace (1989) Gene 4: 560; Barringer et al (1990) Gene 89: 117. Improved methods for in vitro cloning of amplified nucleic acids are described in Wallace et al., U.S. Patent No. 5,426,039, Nucleic acids encoding the PAD polypeptide of the invention, or subsequences of these nucleic acids, can be prepared for any suitable method as described above, including, for example, cloning and restriction of suitable sequences A nucleic acid encoding a PAD polypeptide can then be introduced either into a cell prokaryotic or eukaryotic host through the use of a vector, plasmid or construct and the like to produce a PAD polypeptide of the invention. A typical expression cassette contains a promoter operably linked to a nucleic acid encoding the glycosyltransferase or other enzyme of interest. Expression cassettes are typically included in expression vectors that are introduced into suitable host cells, including for example, bacterial, insect, fungal, plant or animal cells. Promoters either constitutive or regulated may be used in the present invention. Promoters suitable for use in eukaryotic host cells are well known to those skilled in the art. The expression vectors of the invention can be transferred to the selected host cell by methods known to those skilled in the art including, for example, calcium phosphate transfection, DEAE-dextran-mediated transfection, transfection, microinjection, lipid mediated transfection. cationic, electroporation, transduction, charge, ballistic introduction, infection or other methods. (See Molecule Cloning: A Labora tory Manual, 2nd ed., Vol 1-3, ed. Sambrook et al., Cold Spring Harbor Laboratory Press (1989)). Transformed cells can be selected, for example, by resistance to antibiotics conferred by genes conferred on the plasmids, such as the amp, gpt, neo and hyg genes.

A PAD polypeptide, homolog, fragments or other derivatives, or variants thereof, or cells expressing it can be used as an antigen to produce antibodies against it. The present invention includes, for example, monoclonal and polyclonal, chimeric, single chain antibodies, as well as Fab fragments. Thus, the present invention also encompasses a method for generating antibodies directed against one or more PAD polypeptides described above, which comprise providing a PAD polypeptide or a homolog or derivative or biologically functional variant thereof and administering the polypeptide in an animal subject. in an amount sufficient to induce an immune response to generate antibodies directed against the PAD polypeptide. Thus, the invention includes a method for generating antibodies against a protective antigenic determinant (PAD) of PRRSV including administering to an animal a first GP5-M heterodimer, wherein the GP5 of the first GP5-M heterodimer has a glycosylation at position 44 of GP5 of a North American PRRSV (NA) or glycosylation at position 46 of GP5 of a European PRRSV (EU). The method also includes administering to the animal a second GP5-M heterodimer, wherein the GP5 of the second GP5-M heterodimer has no glycosylation at position 44 of GP5 of an American PRRSV (NA), or at position 46 of GP5 of a European PRRSV (EU). The inventors also contemplate that amino acids 51 and 53 in GP3 in NA and EU PRRSV respectively may be important for use as a PAD and believe that they may be involved in viral binding and that VN antibodies may react with them. The PADs of the invention can be immunized according to the immunization protocol described herein. In another aspect of the invention, the animal is a non-human, for example, a rat, horse, cow, mouse, pig, sheep, rabbit or chicken. Thus, the invention provides antibodies that selectively bind to the PAD polypeptide, a derivative, a homologue or a variant as well as fragments thereof. These antibodies can be used to quantitatively or qualitatively detect the PAD polypeptide or variants as previously described. Many methods are known to generate and / or identify antibodies against a given target peptide, such as a PAD polypeptide. Several of these methods are described by Harlow, An tibodies, Col Spring Harbor (1989). The full length PAD polypeptide, derivative, homolog or variant or fragments in a fusion protein can be used. For the preparation of monoclonal antibodies, any technique known in the art that provides antibodies produced by continuous cell line cultures can be used. Examples include various techniques, such like those in Kholer, G. and Mi lstein, C. Na ture 256: 495-497 (1975); Kozbor et al., Immunology Today 4: 72 (1983); (Cole et al., Pp. 77-96 in Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, Inc. (1983).) Monoclonal antibodies can be produced by hybridomas, which are immortalized cell lines capable of treating a monoclonal antibody. The immortalized cell lines can be created in vitro by fusing two different cell types, usually lymphocytes, one of which is a tumor cell.The anti-PAD antibodies can comprise polyclonal antibodies.The methods for preparing polyclonal antibodies are known by the skilled person Polyclonal antibodies can be developed in a mammal, for example, by one or more injections of an immunizing agent and, if desired, an adjuvant Typically, the immunizing agent and / or adjuvant will be injected into the mammal by several subcutaneous or intraperitoneal injections.The immunizing agent may include the PAD polypeptide, or derivative, a homologue or a variant as well as fragments or a fusion protein thereof. It may be useful to conjugate the immunizing agent to a protein known to be immunogenic in the mammal being immunized. Examples of these immunogenic proteins include but are not limited to, lava emotion. navy, serum albumin, bovine thyroglobulin and soybean trypsin inhibitor. Examples of adjuvants that can be employed include Freund's complete adjuvant and MPL-TDM adjuvant (monophosphoryl lipid A, synthetic trehalose dicorinomycolate). The immunization protocol can be selected by one skilled in the art without undue experimentation. In another embodiment of the present invention, there is provided a method for preparing a vaccine against PRRSV. In one aspect, the method comprises providing a PAD polypeptide, a derivative, a homologue or a variant and fragments thereof. Alternatively, the method for preparing a PRRSV vaccine may include mixing PAD polypeptide with a physiologically acceptable carrier or diluent. Generally, vaccines are prepared as injectables, in the form of aqueous solutions or suspensions. Vaccines in an oil base are also well known such as for inhalation. Solid forms that dissolve or suspend before use can also be formulated. Pharmaceutical or physiological vehicles • are generally added that are compatible with the active ingredients and acceptable for pharmaceutical use. Examples of these vehicles include, but are not limited to, water, saline solutions, dextrose or glycerol. You can also use vehicle combinations. Someone of ability Ordinary in the art will be familiar with pharmaceutically or physiologically acceptable carriers or diluents. In view of the foregoing, the present invention also provides a vaccine. In another embodiment, a vaccine is provided that includes at least one PAD polypeptide, a derivative, a homolog or a variant or fragment thereof. In another aspect, the vaccine comprises a nucleic acid encoding a PAD polypeptide, a derivative, a homolog or a variant or fragment thereof. The present invention provides vaccines that are killed (inactivated), attenuated (modified alive), subunit, DNA or based on recombinant vectors. The invention provides in one more aspect a vaccine for use in the protection of pigs against disease conditions resulting from a PRRSV infection. The vaccines of the present invention are generally designed to be a prophylactic treatment that immunizes pigs against diseases caused by virulent strains of PRRSV. However, the vaccines are also designed for the therapeutic treatment of pigs already infected with a virulent strain of PRRSV. The present inventors contemplate that the treatment and prevention of PRRSV can be based on a completely different theory than current vaccine strategies, for example, strategies that include associated mechanisms and either with cell-mediated immunity (CMI) and / or virus neutralizing antibodies (VN). The inventors believe that the PRRSV has a "glucan shield" that can either block or protect the neutralizing epitopes (NE). The shield prevents the humoral immune response from recognizing key neutralizing epitopes containing glucans linked to asparagine or other sugar portions, so neutralizing epitopes are not available for the generation of neutralizing antibodies. The inventors also believe that PRRSV has an NE block glucan in some situations (Figure 17). When a "species jump" occurs in a host by an RNA virus, the neutralizing antibody (Nab) against the NE can be easily induced (Figure 16). These first "species jump" trains without glucans in the block or shield positions are easily eliminated by Nab against NE. Upon infecting a new host species or developing quasi-species, the NE becomes blocked (BNE) by glucans in direct proximity (conserved region) of the NE (Figure 17), for example, the sequence of HLV013 in Figure 10. Subsequently, Nab is created against BNE. Then a glucan shield (SNE) emerges in quasi-emergent species in hypervariable regions near the NE. Thus, Nab may be slow to develop and / or ineffective against escape mutants containing both BNE and SNE (figure 19). If only the glucan shield is present, for example, rare wild type mutants, then Nab is induced to the NE (Figure 19), for example, HLV093. See figure 11. This Nab protects against strains only with the glucan shield. Thus, strains with only one shield of glucans are not maintained in the susceptible host population. Sequential immunization of wild-type mutants that do not use glucan shields (BNE [figure 17] followed by NE [figure 18]) results in polyclonal Nab that protects against predominant emerging heterologous virus strains and provides cross-reactivity (figure 19). Thus, viruses emerge by first forming a glucan block and then a glucan shield (Figure 19). Heterologous nab can be produced by first inoculating a glucan-blocked epitope (BNE) without a glucan shield followed by NE without the glucan block that is referred to as an inverse epitope evolution immunization. Thus, the present inventors believe that when a pig is exposed to an initial strain and then to a subsequent different strain of PRRSV that is more glycosylated in the hypervariable ectodomain of GP5, the pig immune system recognizes only non-glycosylated regions in GP5 and M. in the neutralizing epitope and epitopes shared between two serotypes. As a consequence, the immune system is unable to recognize new glycosylated epitopes in PRRSV resulting in ineffective immunity. The present inventors are the first to recognize that this theory can be exploited for use in the development and administration of individual or multivalent PRRSV vaccines and PRRSV immunization schemes using typing glycans of PRRSV isotypes. Thus, the glycosylation patterns (types of glucans) of PRRSV can be used for the initial clustering of PRRSV strains. According to the present invention, strains of PRRSV within the North American and European genotypes are grouped based on their glycosylation patterns. This discovery is referred to by the inventors as a glycan typing scheme. Glucan typing is a more accurate means of detecting strains of heterologous PRRSV when new strains emerge in the population than the sequence homology of ORF5. The present inventors contemplate that the discernment of glycosylation patterns can be used in individual or multivalent vaccines or in the development of vaccination schedules and protocols. In one aspect, the strains are classified based on whether they are European or North American strains. In another aspect of typing PRRSV strains, the first letter is either EU (European type) or NA (North American type) to designate the group of genotype. As used herein, "U.S." refers to PRRSV isotypes characterized by glucans preserved at position 46, 53 or both in GP5. As used herein, NA refers to PRRSV isotypes characterized by glucans preserved at position 44, 51 or both in GP5. Each strain is given a number corresponding to the number of glycosylation sites located in the ectodomain of the amino acid sequence of GP5 shown in Table 7, but excludes the highly conserved glycans located at amino acid 44 and 51 for NA strains and amino acid 46 and 53 for EU strains. Thus, NA-0 refers to the GP5 ectodomain of the NA strain that does not have glucans and EU-0 refers to the GP5 ectodomain of a EU strain that does not have glucans. For example, NA-1 refers to the GP5 ectodomain of a North American strain that has 1 glucan located in the GP5 ectodomain excluding highly conserved glycans located at amino acid 44 and 51 for NA strains. The present invention also contemplates that newly identified PRRSV strains can be typed by glucans using the methodology described above and consequently used in embodiments of the present invention. The inventors also contemplate that the typing schemes with glucans described herein may also be applicable to treat or prevent other viruses that use a "glucan shield" to evade the system immunological, for example, to design immunization protocols. New or known PRRSV strains can also be isolated from the field using standard techniques and methods known in the art. In accordance with the invention, virulent or avirulent PRRSV can be used in a vaccine or in an immunization protocol. The inventors have found that this method of administering viral strain of PRRS with N-glycosylation in the ectodomain of GP5, in particular a glucan at position 44 (or 46) depending on whether the GP5 mimics a North American or European PRRSV strain in the GP5-M heterodimer to vaccinate pigs is particularly able to reinforce an immune system of a pig to develop a greater immune response when it has been followed by the administration of a PRRSV strain that does not have glycosylated amino acids in the GP5 ectodomain and subsequently attacked with a PRRSV having glycosylation ectodomain in its GP5 polypeptide. See table 6. This rationale is based on the fact that glucans in the hypervariable region of GP5 can inhibit / delay a protective antibody response to PAD. In addition, it is believed that the absence of a glucan at position 44 contributes to protection against heterologous strains of the virus. For example, a strain such as HLV093 that is deficient of glucans in its neutralizing epitope in GP5 can be used to prime the immune response before finding other types of PRRSV glucans. For example, a strain such as HLV013 that is deficient in glucans in its hypervariable region (1-37) in GPs can be used to prime the immune response before finding other types of PRRSV glycans. In one aspect of the immunization protocol against a PRRSV infection, a virus having a PAD of a GP5-M heterodimer of PRRSV of the present invention with glycosylation at position 44 of GP5 in a North American strain is administered, followed by administration of a virus having a PAD of a GP5-M heterodimer of PRRSV of the present invention without glycosylation at position 44 of GP5 in a North American strain, and then attacked with a PRRSV having glycosylation in the neutralizing epitope of GP5. In another aspect, a virus having a PAD of a GP5-M heterodimer of PRRSV of the present invention is administered with glycosylation at position 46 in GP5 in a European strain, followed by administration of a virus having a PAD of a GP5-M heterodimer of PRRSV of the present invention without glycosylation at position 46 in GP5 in a European strain, and then it is attacked with a PRRSV having glycosylation in the neutralizing epitope of GP5. In one aspect of the immunization protocol against a PRRSV infection, a PAD comprising a GP5-M heterodimer of PRRSV of the present invention with glycosylation at position 44 of GP5 in a North American strain, followed by administration of a PAD comprising a GP5-M heterodimer of PRRSV of the present invention without glycosylation at position 44 of GP5 in a North American strain, and then it is attacked with a PRRSV strain having glycosylation in the neutralizing epitope of GP5. In another aspect, a PAD having a GP5-M heterodimer of PRRSV of the present invention is administered with glycosylation at position 46 of a GP5 in a European strain, followed by the administration of a PAD comprising a GP5-M heterodimer of PRRSV of the present invention without glycosylation at position 46 of GP5 in a European strain, and then attacked with a PRRSV strain having glycosylation in the neutralizing epitope of GP5. In one embodiment of the invention, a PAD of GP5 may not have glucans of amino acids 1-35 in the NA PRRSV GP5 protein. In another aspect, a PAD of GP5 may have a glucan at position 44 in the GP5 protein of NA PRRSV. In another aspect, a PAD of GP5 can have a glucan at position 44 in GP5 of NA PRRSV and have glucans present or absent in amino acids 1-35 in the GP5 protein of NA PRRSV, for example, as found in some strains of NA PRRSV. In one embodiment of the invention, a PAD of a GP5-M heterodimer may not have glucans of amino acids 1-35 in the GP5 protein of NA PRRSV. In another aspect, a GP5-M heterodimer PAD can have a glucan at position 44 in the GP5 protein of NA PRRSV. In another aspect, a GP5-M heterodimer PAD can have a glucan at position 44 in the GP5 of NA PRRSV and have glycans present or absent in amino acids 1-35 in the GP5 protein of NA PRRSV, for example, as found in some strains of NA PRRSV. In one embodiment of the invention, a PAD of GP5 may not have glucans of amino acids 1-37 in the GP5 protein of EU PRRSV, as found in EU PRRSV. In another aspect, a PAD of GP5 can have a glucan at position 46 in the GP5 protein of EU PRRSV. In another aspect, a PAD of GP5 can have a glucan at position 46 in GP5 of EU PRRSV and have glucans present or absent in amino acids 1-37 in the GP protein of EU PRRSV, for example, as found in some strains of EU PRRSV. In one embodiment of the invention, a GP5-M heterodimer PAD may not have glucans of amino acids 1-37 in the GP5 protein of EU PRRSV, as found in Lelystad. In another aspect, a GP5-M heterodimer PAD can have a glucan at position 46 in the GP5 protein of EU PRRSV. In another aspect, a GP5-M heterodimer PAD can have a glucan at position 46 in the EU GP5.

PRRSV and have glucans present or absent in amino acids 1-37 in the GP5 protein of EU PRRSV, for example, as found in some strains of EU PRRSV. The present PRRSV immunization process is suitable since it results in the generation of high levels of neutralizing antibodies in an early antibody response when they are attacked with PRRSV from several strains that provide heterologous reactivity. It is believed that the immunization protocols described herein can be applied to the treatment and prevention of other viral infections, including, but not limited to HIV and influenza. Thus, the strains that include and similar to HLV013 may or may not provide direct protection against all other types of glucans but rather an indirect protection by enlisting the immune system to progressively find PAD of PRRSV with varying degrees of masking of glucans. In contrast, the subsequent inoculation of PAD of different strains similar to HLV093 in glycosylation of the hypervariable ectodomain of GP5 can provide access to important neutralizing epitopes in all PRRSV strains, such as those most glycosylated in the hypervariable ectodomain of GP5. In this way, the typing of PRRSV glycans creates a classification or order or combination of effective PRRSV administration for generate an immune response to several PRRSV. In one aspect of the present invention, several GP5-M (Glycan types) hodyodimers may be required to induce widespread protection against a variety of PRRSV strains. Without wishing to be limited by this theory, the present inventors believe that all immunogens representing the different types of GP5 glycans may have to occur together due to the concept of "original antigenic sin" (OAS) wherein the antibody response developed in response to a second viral infection reacts more strongly than the original variant infection. Thus, the present inventors contemplate that the immune system of the pig can be prepared with a single PAD or immunization with several PADs to obtain a broader and more reactive immune response than immunization with a single PAD. The use of a multivalent vaccine strategy can derive the original antigenic sin. Thus, according to the invention, several strains of PRRSV or PAD can be administered simultaneously or sequentially. For the treatment of PRRSV or the induction of protective antibodies against all epitopes of PAD, pigs may require exposure to several types of glucans of GP5, M or GP5-M heterodimer. In one embodiment of the invention, a method is provided for identifying GP5-M heterodimers that develop protection against PRRSV. This method also includes fragments, derivatives or homologs of the GPS-M protein or GP5-M heterodimers. In one aspect, the method comprises administering to a test pig a first GP5-M heterodimer, wherein GP5 has glycosylation at position 44 of GP5 of an American porcine reproductive and respiratory syndrome (PRRSV) virus (NA) or glycosylation at position 46 of GP5 of a European PRRSV (EU). The administration of the first GP5-M heterodimer of the test pig is followed by the administration of a second GP5-M heterodimer, where the GP5 of the second GP5-M heterodimer has no glycosylation at position 44 of GP5 of a North American PRRSV (NA ) or in position 46 of GP5 of a European PRRSV (EU). The test and control pigs are subsequently attacked with an infectious amount of a virus that causes PRRS, for example, Lelystad. Someone skilled in the art will be familiar with the strains of PRRS that cause PRRS and the route and doses necessary to achieve infection. The method also includes determining whether the first and second administered GP5-M heterodimers are effective in protecting a pig against PRRSV attack. Various methods and techniques for determining whether GP5-M heterodimers provided protection against PRRSV infection are known to those skilled in the art, including but not limited to, observing a difference between test pig and control in PRRS symptoms, for example, clinical signs or symptoms of PRRS comprising weight loss, reduced weight gain, lethargy, respiratory distress, "tachycardia" (forced expiration), fevers, rough coats, sneezing, cough, ocular edema, conjunctivitis, microscopic lung lesions due to large lesions, myocarditis, lymphadenitis, encephalitis and rhinitis. A reduction in any of the PRRS symptoms observed in the test pig compared to the control pig indicates that the first and second administered GP5-M heterodimers provide a degree of protection against PRRS. Similar symptoms or an increase in any of the PRRS symptoms observed in the test pig compared to those observed in the control pig indicate that the first and second GP5-M heterodimers administered do not provide protection against PRRS. In another aspect, determining whether the GP5-M heterodimers provided protection against PRRSV infection includes determining the presence or absence of PRRSV attack in the test pig by electron microscopy or antibodies or assays such as the fluorescent focus neutralization test (FFN). ) or the Western blot assay for the heterodimer can be used to give an indication of the production and protection of heterologous antibodies. The presence of attack PRRSV indicates that the first and second GP5-M heterodimers administered are not effective in protecting against PRRS and the absence of PRRSV attack indicates that the first and second administered GP5-M heterodimers are effective in protecting against PRRS. The present inventors also contemplate that the GP5-M heterodimers of the present invention can be delivered using various vectors and viruses, for example, PRRSV. Thus, another aspect of the invention includes a method for identifying viruses that develop protection against PRRSV. These identified GP5-M heterodimers or viruses can be used in an immunization protocol or PRRSV vaccine. For example, a PRRSV comprising a GP5-M heterodimer with N-glycosylation in the GP5 ectodomain, in particular a glucan at position 44 for an NA PRRSV or 46 for an EU PRRSV can be administered to a pig. The method also includes administering an NA or EU PRRSV strain that does not have glycosylated amino acids at position 44 or 46 in GP5. To determine whether the viruses provide protection to a pig that was given these "test" viruses, it can be attacked with a PRRSV, or any virus that causes PRRS, and any PRRS symptoms observed and compared with a control pig that receives the attack virus to determine if the "test" virus provides protection against PRRSV. In another aspect, a method of the invention includes identify a virus or PAD that develops protection against PRRSV for use in an immunization protocol or vaccine by administering fragments, derivatives or homologs of GP5 having a glucan at position 44 for an NA PRRSV or 46 for an EU PRRSV as a heterodimer, for example, with an M protein of PRRSV followed by the administration of a GP5 heterodimer that does not have glycosylated amino acids at position 44 or 46 in GP5. To determine if the PADs provide protection to a pig to which this "test" PAD was administered, it can be attacked with a PRRSV, for example, Lelystad or any virus that causes PRRS, and observe any PRRS symptoms and compare these symptoms with a control pig that receives the attack virus to determine if the "test" PADs provide protection against PRRSV. Protection can also be determined using an incidence of morbidity and mortality. The present inventors contemplate that any combination of PRRSV killed (inactivated), attenuated PRRSV (live modified), subunit, DNA or recombinant vector based on having a GP5, M or GP5-M heterodimer can be typed by glucans and used in the protocol or progressive or sequential or combinatorial immunization scheme described herein. In one aspect, the immunization protocol or scheme induces antibodies against the PAD.

The present inventors contemplate that strains of European-type PRRSV can be typed by glucans analogously (table 7) and used in an immunization protocol for pigs as described for the American PRRSV. In accordance with the present invention, one embodiment of a PRRS vaccine includes an attenuated PRRSV with a GP5, M or GP5-M heterodimer as described herein. The property of an attenuated strain to induce disease conditions associated with PRRS as described above is significantly reduced or completely absent if the strain is a live attenuated virus. Therefore, it is desirable that particular live PRRSV vaccines comprise an attenuated PRRSV strain that generates an immune response to the GP5, M or GP5-M heterodimer of the attenuated PRRSV strain without causing disease. Methods for making attenuated viruses are well known in the art and include methods such as serial passage in cell culture on a suitable cell line or chemical mutagenesis. For example, attenuated variants of PRRSV can be produced by serial passage of the virus in a cell line, for example, Marc 145, CL2621, MA-104 cells, or porcine alveolar macrophages for about 10 and 100 steps in such a way that they accumulate mutations that confer attenuation in the strain. Passages in series refers to the infection of a cell line with an asylated virus, the recovery of the viral progeny of the host cells, and the subsequent infection of host cells with the viral offspring to generate the following passage. During the passage in the cell line, the virus loses its ability to cause disease in the pig, that is, it becomes apatogenic or non-pathogenic, while retaining its ability to replicate in the pig and produce a protective immune response. Therefore, to make a vaccine, the attenuated PRRSV isolate is cultured in cell culture in a suitable cell line, ie Marc 145, CL2621 or MA-104 cells, at sufficient titres to produce a vaccine. The PRRSV is harvested according to methods well known in the art. For example, the virus can be removed from the cell culture and separated from cellular components, typically by well-known clarification procedures, for example, centrifugation, and can be further purified as desired using methods well known to those skilled in the art. The PRRSV can then be concentrated, frozen and stored at -70 ° C or lyophilized and stored at 4 ° C. The isolation of an attenuated virus can be followed by a sequence analysis of its genome to determine the basis for the attenuated phenotype. This is achieved by sequencing the viral DNA and identifying nucleotide changes in the attenuated isolate in relation to the genomic sequence of a control virus. Therefore, the molecular changes that confer attenuation in a virulent PRRSV strain can be characterized. One embodiment of the invention provided herein includes the introduction of sequence changes in any of the positions alone or in combination, to thereby generate offspring of attenuated virus in known PRRSV strains or those that will be identified and isolated. Viral genomes with these alterations can be produced by any standard recombinant DNA technique known to those skilled in the art (Ausubel et al., Current Protocols in Molecular Biology, Geene Publishing Associates &Wiley Interscience, New York, 1989) for introduction of nucleotide changes in cloned DNA. A genome can then be ligated into a vector suitable for transfection in host cells in the production of viral progeny. The PRRSV before vaccination is mixed with a suitable dose and may include a pharmaceutically acceptable carrier, such as a saline solution and / or an adjuvant, such as aluminum hydroxide. Thus, the PRRSV vaccines of the invention may include an immunogenically effective amount of one or more attenuated PRRSVs as described in the present. The composition of attenuated viruses can be introduced into a pig, with a vehicle and / or physiologically acceptable adjuvant. Useful carriers are well known in the art and include, for example, water, pH regulated water, saline, glycine, hyaluronic acid and the like. The resulting aqueous solutions can be packaged for use as such, or lyophilized, the lyophilized preparation being rehydrated before its administration, as mentioned above. The compositions may contain pharmaceutically acceptable auxiliary substances as required to approximate physiological conditions, such as pH adjusting and regulating agents, tonicity adjusting agents, wetting agents and the like, eg, sodium acetate, sodium lactate, sodium chloride, potassium chloride, calcium chloride, sorbitan monolaurate, triethanolamine oleate and the like. Administration of the live attenuated viruses described herein can be carried out by any suitable means, including either parenteral injection (such as parenteral, subcutaneous or intramuscular injection) or topical application of the virus (typically carried out in the pharmaceutical formulation) to an airway surface. Topical application of the virus to an airway surface can be carried out by intranasal administration (for example, by the use of a dropper, swab or inhaler that deposits a pharmaceutical formulation intranasally). Topical application of the virus to an airway surface can also be accomplished by administration by inhalation, such as by creating respirable particles of a pharmaceutical formulation (including both liquid particles and solid particles) containing the virus as an aerosol suspension. , and then causing the subject to inhale the respirable particles. Methods and apparatuses for administering respirable particles of pharmaceutical formulations are well known, and any conventional technique can be employed. As a result of vaccination, the host becomes at least partially or completely immune against PRRSV infection of the serotypes administered, or resistant to developing moderate or severe PRRSV infection. In another embodiment, the attenuated PRRSV of a particular strain having a desired PAD as described herein may be combined with attenuated viruses from other strains of PRRSV having the desired PADs as described herein to achieve protection against various PRRSV. According to the present invention, the different PRRSVs can be administered sequentially or progressively or alternatively simultaneously in a mixture. Sequential or progressive administration of the vaccine compositions of the invention may be required to develop sufficient levels of immunity against various strains of PRRSV. Individual or multiple administration of the vaccine compositions of the invention can be carried out. Multiple administration may be required to develop sufficient levels of immunity. Induced immunity levels can be monitored by measuring the amount of secretory and serum neutralizing antibodies, and doses adjusted or repeated vaccinations as necessary to maintain desired levels of protection. The property of an attenuated strain to induce disease conditions associated with PRRS as described above is significantly reduced or completely absent if the strain is in an inactivated form. In accordance with the present invention, one embodiment of a PRRSV vaccine includes an inactivated PRRSV (killed) with a GP5, M or GP5-M protein heterodimer. The property of an inactivated strain to induce disease conditions associated with PRRS as described above is significantly reduced or completely absent if the strain is inactivated (killed). Inactivation of a PRRSV strain can be achieved by a variety of methods including freeze / thaw, chemical treatment (for example, treatment with thimerosal or formalin), sonication, radiation, heat or any other means of convention sufficient to prevent the replication or growth of the virus while preserving the immunogenicity of the PRRSV strain. The inactivated vaccine is made by methods well known in the art. For example, once the virus is propagated to high titers, it would be readily apparent to those skilled in the art that the antigenic mass of virus could be obtained by methods well known in the art. For example, the antigenic mass of PRRSV can be obtained by dilution, concentration or extraction. PRRSV can be inactivated by treatment with formalin or binary ethylenimine (BEI), both methods are well known to those skilled in the art. For example, the inactivation of a PRRSV strain by formalin can be carried out by mixing the PRRSV suspension with 37% formaldehyde to a final formaldehyde concentration of 0.05%. The PRRSV-formaldehyde mixture is mixed by constant stirring for about 24 hours at room temperature. The inactivated PRRSV mixture is then tested for residual live virus by growth assay on a suitable cell line, for example, Marc 145, CL2621 or MA-104 cells. The inactivation of a PRRSV strain by EIB is it can be carried out, for example, by mixing the PRRSV suspension of the present invention with 0.1 M BEI (2-bromoethylamine in 0.175 N NaOH) to a final BEI concentration of 1 mM. The PRRSV-BEI mixture is mixed by constant fixation for approximately 48 hours at room temperature, followed by the addition of 1.0 M sodium thiosulfate to a final concentration of 0.1 mM. Mixing was continued for 2 more hours. The inactivated PRRSV mixture is tested for residual living PRRSV by assaying growth in a suitable cell line, eg, Marc 145 cells. The inactivated PRRSV mentioned above of the present invention can be mixed with any of the pharmaceutically acceptable adjuvants or physiological carriers. to formulate inactivated virus vaccines at the appropriate dose level. Suitable formulations and modes of administration of the killed PRRSV vaccine are described below. In one embodiment, a PRRSV vaccine of the present invention can be a subunit vaccine. In one aspect, the subunit is a GP5, M, or GP5-M heterodimer of PRRSV. Viral subunits can be obtained from PRRSV using biochemical methods or can be expressed by recombinant methods in suitable cells, e.g., eukaryotic cells. Methods for expressing viral subunits are common in the art. For example, methods for expressing viral subunits are described in the following articles and in the references cited there: Poss, 1986, Virus research 5:43; Kuroda et al., 1986, EMBO J. 5: 1359; Doerfler, 1986, Curr. Microbiol. Immunol. 131: 51; Rugby, 1983, J. Gen. Virol. 64: 255, Mackett et al., 1985, In: DNA Cloning, A Practical Approach, vol. II, Ed., D. M. Glover, IRL Press, Washington, D.C .; Rothestein, 1985, In: DNA Cloning, A Practical Approach, cited above; Kinney et al., 1988, J. Gen. Virol. 69: 3005; Panical et al., 1983, Proc. Nati Acad. Sci. USA 80: 5364; Small et al., 1985, In: Vaccinia Viruses as Vectors for Vaccine Antigens, p. 175-178, Ed. J. Quinnan, Elsevier, N.Y. In the practice of one embodiment of this invention, the subunit of GP5, M or GP5-M heterodimer can be produced in vitro by recombinant techniques in large quantities sufficient for use in a subunit vaccine. In another aspect, the subunit of GP5, M or GP5-M heterodimer can be expressed by a recombinant vector, viral vector or virus. In another aspect, the recombinant vector, viral vector or virus expressing the subunit can in turn serve as a vaccine component that acts as an antigen or an adjuvant and develops or increases the immune response of the pig to a protein GP5, M or GP5-M heterodimer alone. In a further embodiment of the present invention, the The vaccine comprises a recombinant virus vector containing a nucleic acid encoding the antigen of a GP5, M or GP5-M heterodimer or immunogenic fragment thereof of a PRRSV strain. Suitable recombinant viral vectors include, but are not limited to live adenoviruses, poxviruses, baculoviruses, pseudorabies viruses (PRV), Venezuelan equine encephalitis vectors (VEE) such as strains V3526 or TC-83, and viral replicon particles (VRP). ) derived from VEE, equine arteritis virus (EAV), or transmissible gastroenteritis virus (TGE). The recombinant virus of the present invention can also contain several copies of a glucan type of a subunit of GP5, M or GP5-M heterodimer. Alternatively, the recombinant virus can contain more than one type of glucan of the subunit of GP5, M or GP5-M heterodimer, such that the virus can express two or more subunits of GP5, M or GP5-M. In one aspect, subunits of GP5, M or GP5-M can vary in glycosylation of the ectodomain of the GP5 protein. In the construction of the viral vector of the present invention, the subunit sequence of the GP5, M protein or GP5-M heterodimer is preferably inserted into a viral strain under the control of an expression control sequence in the virus itself. The techniques used to insert the subunit sequence of GP5, M or heterodimer of GP5-M in the viral vector and making alterations in the viral DNA, for example, to insert linker sequences and the like, are known to those skilled in the art. See, for example, T. Maniatis et al., "Molecular Cloning, A Laboratory Manual," Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y. (1982). Thus, given the descriptions contained herein, construction of suitable viral expression vectors for the expression of a GP5, M subunit protein or GP5-M heterodimer is within the capability of the art. The recombinant virus itself, constructed as described above, can be used directly as a vaccine component. According to this embodiment of the invention, the recombinant virus, which contains the subunit of GP5, M or heterodimer of GP5-M, is introduced directly into the target pig by vaccination. The recombinant virus, when introduced into a target pig directly, infects pig cells and produces the subunit of GP5, M or GP5-M heterodimer in pig cells. To make a recombinant viral vector expressing the GP5 antigen, M or GP5-M heterodimer or immunogenic fragment thereof, a DNA encoding the GP5 antigen, M or GP5-M heterodimer or immunogenic fragment thereof is inserted into the viral vector genome, for example, live adenovirus, poxvirus, baculovirus, virus pseudorabies (PRV), vectors of Venezuelan equine encephalitis (VEE) as strains V3526 or TC-83 and viral replicon particles (VRP) derived from VEE, equine arteritis virus (EAV) or transmissible gastroenteritis virus (TGE). Recombinant viral vectors can be reproduced by standard recombinant DNA techniques recognized by those skilled in the art (Ausubel et al., Current Protocols in Molecular Biology, Greene Publishing Associates &Wiley Interscience, New York, 1989) for the introduction of changes in nucleotides in cloned DNA. A viral genome can then be ligated into a suitable vector for transfection into host cells for the production of viral progeny. For any of the recombinant virus vectors mentioned above, the cDNA encoding the GP5 antigen, M or GP5-M heterodimer or immunogenic fragment thereof is operably linked to a eukaryotic promoter at the 5 'end of the cDNA encoding the antigen and a eukaryotic termination signal and the poly (A) signal at the 3 'end of the cDNA encoding the antigen. As used herein, the term "operably linked" means the polynucleotide of the present invention (such as a cDNA molecule) and a polynucleotide (DNA containing an expression control sequence, eg, transcription promoter and Termination sequences are placed in a vector or cell in such a way that the expression of the antigen encoded by the cDNA is regulated by the expression control sequence. Methods for cloning DNA such as the cDNA encoding the GP5 antigen, M or GP5-M heterodimer or immunogenic fragment thereof and operably linked to DNA containing expression control sequences thereto are well known in the art. Examples of suitable promoters for expressing the GP5-M antigen or GP5-M heterodimer or immunogenic fragment thereof in the recombinant viral vectors are the cytomegalovirus immediate early virus (CMV) promoter, the promoter of the long terminal repeat of the virus of the Routh's sarcoma (RSV-LTR), the immediate-early promoter of simian virus 40 (SV40), and inducible promoters such as the metallothionein promoter. An example of a DNA having a poly (A) termination and signal is the late poly (A) SV40 region. Another example of a suitable viral expression system for producing the antigen is the Sindbis expression system available from Invitrogen. The use of these commercially available expression vectors and systems is well known in the art. In a further embodiment of the present invention, the vaccine is provided as a vaccine of nucleic acid molecule or DNA that develops an active immune response to the pig. The DNA molecule vaccine consists of a DNA having a nucleic acid sequence encoding the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof. The nucleic acid encoding the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof is operably linked at or near the start codon for the antigenic determinant of GP5, M or GP5-M heterodimer which makes possible the transcription of the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof from nucleic acid when the nucleic acid is inoculated into the cells of the pig. Preferably, the DNA molecule is in a plasmid. Promoters that are useful for DNA vaccines are known in the art and include, but are not limited to, the RSV LTR promoter, the CMV immediate early promoter and the SV40 T antigen promoter. In one aspect, the nucleic acid can be operably linked at or near the stop codon of the coding sequence for the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof to a nucleic acid fragment comprising a signal of transcription termination and a Poly (A) recognition signal. The DNA vaccine is provided to the pig in an accepted pharmaceutical vehicle or in a lipid or liposome vehicle similar to those described in the U.S. patent. Do not. ,703,055 to Felgner. The DNA vaccine can be provided to the pig by a variety of methods such as intramuscular injection, jet injection, or biolistic bombardment. The preparation of DNA vaccines and methods for their use is provided in the patents of E.U.A. Nos. 5,589,466 and 5,580,859, both to Felgner. Finally, a method for producing a pharmaceutical grade plasmid method is shown in the patent of E.U.A. No. 5,561,064 to Marquet et al. Therefore, using any suitable method including those mentioned above, DNA vaccines expressing the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof are used to immunize pigs against PRRSV. The advantage of the DNA vaccine is that the DNA molecule conveniently propagates as a plasmid which is a simple economical means of producing a vaccine, and since the vaccine is not alive, many of the regulatory aspects associated with vector vaccines Live recombinant viruses are not an aspect of DNA vaccines. One skilled in the art would appreciate that the DNA vaccine of the present invention can comprise synthetically produced nucleic acids which are made by chemical synthesis methods well known in the art. In a further embodiment of the present invention, the vaccine consists of the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof isolated and purified. Preferably, the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof is produced in a recombinant bacterium or eukaryotic expression vector that produces the antigen that is isolated and purified to make the vaccine. For example, the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof is produced in a microorganism such as bacteria, yeast or fungi; in a eukaryotic cell such as a mammalian or insect cell or in a recombinant virus vector such as adenovirus, poxvirus, herpesvirus, Simliki forest virus, baculovirus, bacteriophage, sindbis virus, sendai virus, vectors of Venezuelan equine encephalitis ( VEE) such as strains V3526 or TC-83, and viral replicon particles (VRP) derived from VEE, equine arteritis virus (EAV) or transmissible gastroenteritis virus (TGE). Bacteria suitable for producing the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof include Escheri chia coli, Ba ci lus subtilis or any other bacterium that is capable of expressing heterologous polypeptides. Yeast types suitable for expressing the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof include Saccharomyces cerevisiae, Schi zosa ccharomyces pombe, Candida, or any other yeast capable of expressing heterologous polypeptides. Methods for using the bacteria, recombinant virus vectors, eukaryotic cells mentioned above to produce antigens for vaccines are well known in the art. To produce the vaccine consisting of the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof, the nucleic acid encoding the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof is in a plasmid and the nucleic acid is operably linked to a promoter that affects the expression of the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof in a microorganism. Suitable promoters include, but are not limited to, T7 phage promoter, T3 phage promoter, beta-galactosidase promoter and Sp6 phage promoter. The expression of the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof in a microorganism makes it possible for the antigenic determinant of GP5, M or GP5-M heterodimer to be produced using fermentation technologies that are used commercially to produce large amounts of recombinant antigenic polypeptides. Methods for isolating and purifying antigens are well known in the art and include methods such as gel filtration, chromatography of affinity, ion exchange chromatography or centrifugation. To facilitate the isolation of the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof, a fusion polypeptide can be made in which the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof is linked to another polypeptide that makes isolation possible by affinity chromatography. Preferably, a fusion polypeptide is made using one of the expression systems mentioned below. For example, the cDNA nucleic acid sequence encoding the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof is linked either at the 5 'end or the 3' end of a nucleic acid encoding for a polypeptide. The nucleic acids are linked in the proper codon reading frame to make possible the production of a fusion polypeptide in which the amino and / or carboxyl terminus of the antigenic determinant of GP5, M or GP5-M heterodimer or portion thereof is fuse to a polypeptide that allows simplified recovery of the antigen with a fusion polypeptide. An example of a prokaryotic expression system for producing the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof for used in vaccines is the Glutathione S-transferase (GST) Gene Fusion System available from Amersham Pharmacia Biotech, Piscataway, N.J., which uses the expression vector plasmid pGEX-4T-1. The cDNA encoding the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof is fused in the proper codon reading frame with the DNA encoding GST. The GST part of the fusion polypeptide allows rapid purification of the fusion polypeptide using affinity chromatography of glutathione Sepharose 4B. After purification, the GST portion of the fusion polypeptide can be removed by cutting with a site-specific protease such as thrombin or factor Xa to produce a free antigenic determinant of the GST polypeptide. The antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof free of the GST polypeptide is produced by a second round of affinity chromatography of glutathione Sepharose 4B. Another method for producing a vaccine comprising the antigenic determinant of GP5, M or GP5-M heterodimer or immunogenic fragment thereof is a method that links in frame with the cDNA encoding the antigenic determinant, DNA codons coding for polyhistidine. The polyhistidine preferably comprises six histidine residues which allows the purification of the polypeptide from fusion by metal affinity chromatography, preferably nickel affinity chromatography. To produce the antigenic determinant of GP5, M or GP5-M heterodimer or polyhistidine-free immunogenic fragment thereof, a cleavage site such as an enterokinase cleavage site is fused to the appropriate reading frame between the codons coding for the polyhistidine and the codons that code for the antigen. The free antigen of polyhistidine is made by removing polyhistidine by cutting with enterokinase. The free antigen of polyhistidine is produced by a second round of metal affinity chromatography that binds to free polyhistidine. See Motin et al. Infect. Immun. 64: 4313-4318 (1996). The Xpress System available from Invitrogen, Carlsbad, California, is an example of a commercial kit that is available to make and then isolate the polyhistidine-polypeptide fusion protein. Immunogenic compositions that include vaccines can be prepared in a variety of formulations, for example, injectables, liquid solutions or emulsions. Immunogens, for example, GP5, M or GP5-M protein heterodimer can be mixed with pharmaceutically acceptable excipients that are compatible with the immunogens. These excipients may include water, saline, dextrose, glycerol, ethanol and combinations of the same. The immunogenic compositions and vaccines may further contain auxiliary substances, such as wetting or emulsifying agents, pH regulating agents or adjuvants to increase the effectiveness thereof. The immunogenic compositions and vaccines can be administered parenterally, by injection subcutaneously or intramuscularly in any other suitable form. Immunogenic preparations and vaccines are administered in a manner compatible with the dosage formulation, and in such amount as is therapeutically effective, immunogenic and protective. The amount to be administered depends on the subject to be treated, including, for example, the ability of the individual's immune system to synthesize antibodies and, if required, to produce a cell-mediated immune response. The precise amounts of active ingredient required to be administered depend on the practitioner's judgment. However, suitable dosing scales are readily determinable by one skilled in the art and may be in the order of micrograms of the immunogens. Suitable regimens for initial administration and booster doses are also variable, but may include an initial administration followed by subsequent administrations. The dose may also depend on the route of administration and will vary according to the size of the host.

The concentration of the immunogens in an immunogenic composition according to the invention is generally from about 1 to about 95%. Immunogenicity can be significantly improved if the antigens are co-administered with adjuvants, commonly used as a solution at 0.005 to 0.5 percent in pH-regulated phosphate saline. Adjuvants increase the immunogenicity of an antigen but are not necessarily immunogenic themselves. Adjuvants can act by preserving the antigen locally near the site of administration to produce a depot effect that facilitates a slow, prolonged release of antigen to cells of the immune system. Adjuvants can also attract cells of the immune system to a deposit of antigens and stimulate those cells to develop immune responses. Immunostimulatory agents or adjuvants have been used for many years to improve the immune responses of the host to, for example, vaccines. The vaccines of the present invention can be used in conjunction with an adjuvant, for example, lipopolysaccharides, aluminum hydroxide and aluminum phosphate (alum), saponins complexed to membrane protein antigens (immune stimulatory complexes), pluronic polymers with mineral oils, mycobacteria killed in oil mineral, complete Freund's adjuvant, bacterial products such as muramyl dipeptide (MDP) and lipopolysaccharides (LPS), as well as lipid A and liposomes. The ideal adjuvant characteristics include: (1) lack of toxicity; (2) ability to stimulate a long-lasting immune response; (3) manufacturing simplicity and long-term storage stability; (4) ability to develop both MIC and HIR against antigens administered by several routes; (5) synergy with other adjuvants; (6) ability to interact selectively with populations of antigen-presenting cells (APC); (7) ability to specifically develop specific T-helper cell 1 (TH 1) or TH 2 cell-specific immune responses and (8) ability to selectively increase isotype levels of suitable antibodies (eg, Ig (A) against antigens. adjuvant used with the present invention does not have to possess all of these characteristics to be used with the present invention The route of administration for any of the embodiments of the vaccine of the present invention includes, but is not limited to, oronasal, intramuscular, intraperitoneal, intradermal, subcutaneous, intravenous, intraarterial, intraocular and oral as well as transdermal or by inhalation or suppository.The vaccine can be administered by any means including, but not limited to, syringes, nebulizers, mist formers, needleless injection devices or microprojectile bombardment gene guns (biolistic bombardment). In one aspect of the invention, when the vaccine is based on subunits, DNA or recombinant, the present inventors contemplate that it may be possible to use a single M protein and only vary the GPS protein, for example, its type of glucan and still obtain protection against PRRSV. Alternatively, more than one type of PRRSV GP5 glucan can be employed in a vaccine according to the teachings of the present invention. This includes GP5, M or different GP5-M heterodimers of PRRSV as well as several copies of the same GP5, M or GP5-M heterodimer according to the typing of glucans. The present inventors contemplate that any vaccine for treating PRRS of the present invention may further include at least one other vaccine for a pathogen of pigs, eg, swine influenza virus (SIV), porcine circovirus (PCV), Mycoplasma hyopneumoniae or Haemophi l us parasuis. As a measure of potency of the vaccine, an ELISA assay can be performed on a sample taken from a vaccinated individual to determine whether antibodies against a vaccine comprising a PAD polypeptide, a derivative, a homologue or a variant or fragment thereof. they generated anti-PAD antibodies. The sample of the individual is measured against a reference anti-PAD antibody. The potency of the present vaccine can also be measured by determining whether vaccination protects a pig against infection with PRRSV. A vaccine protects a pig against PRRSV infection if, after administration of the vaccine to one or more unaffected pigs, a subsequent attack with a biologically pure virus isolate (eg, VR 2385, VR 2386 or other isolate from virus described below) results in a reduced severity of any strong or histopathological changes (eg, lesions in the lung) and / or symptoms of the disease, as compared to those changes or symptoms typically caused by the isolate in similar pigs that they are not protected (that is, in relation to adequate control). More particularly, the present vaccine may also be effective in administering the vaccine to one or more suitable pigs that require it, then after an appropriate length of time (eg, 1-4 weeks), attacking with a large sample (103 -7 TCID50) of a biologically pure PRRSV isolate. A blood sample is drawn after the attacked pig after about a week, and an attempt to isolate the virus from the blood sample is then carried out. Isolation of the virus is an indication that the vaccine may not be effective, and failure to isolate the virus is an indication that the vaccine may be effective Thus, the effectiveness of the present vaccine can also be assessed quantitatively (i.e., a reduction in the percentage of consolidated lung tissue compared to a suitable control group) or qualitatively (eg, isolation of PRRSV from blood, detection of antigens. PRRSV in a lung, angina or tissue sample from lymph nodes by an immunoperoxidase assay method, etc.) The symptoms of porcine reproductive and respiratory disease can be assessed quantitatively (eg, temperature / fever), semi-quantitatively (by example, severity of respiratory distress) or qualitatively (eg, the presence or absence of one or more symptoms or a reduction in the severity of one or more symptoms, such as cyanosis, pneumonia, cardiac and / or brain injuries, etc.) . Thus, the present invention also provides a method for vaccinating a susceptible host, eg, a pig, against PRRSV, which comprises administering to the host a PAD polypeptide, a derivative, a homologue or a variant or fragment thereof in an effective amount to protect against infection against PRRSV. It will also be recognized by one of ordinary skill in the art that nucleic acids that express for a PAD polypeptide, a derivative, a homologue or a variant or a fragment thereof also they can be used in vaccination. In another embodiment, a method for preventing or treating PRRSV in an animal is provided wherein a therapeutically effective amount of a vaccine, PAD polypeptides or nucleic acids encoding PAD, such as those described above, are administered to the animal. In one aspect, the animal is a pig. The present invention also contemplates that a novel PAD polypeptide, a derivative, a homologue or a variant or fragment thereof or nucleic acids encoding PAD polypeptides of this invention, either alone or with other immunogenic polypeptides, can be administered to an animal , for example a pig, using any number of delivery systems or methods. These include but are not limited to a liposome delivery system, naked delivery system, electroporation, viruses, vectors, viral vectors or an ingestible delivery system in which the PAD polypeptide or nucleic acids encoding PAD are consumed, example, in food or water. Moreover, PAD polypeptides, derivatives, a homologue or a variant or fragment thereof or nucleic acids encoding PAD polypeptides can be administered (or formulated for administration) peritoneally, orally, intranasally, subcutaneously, intradermally, intramuscularly, topically or intravenously, but they can be administered or formulated for administration by means of any pharmaceutically effective route (ie, effectively to produce immunity). In another aspect, the method further comprises the PAD polypeptide, a derivative, a homolog or a variant or fragment thereof encoding a PAD polypeptide that is present in a physiologically acceptable carrier in an amount effective to protect against PRRSV infection. In addition to being used as vaccines, the PAD polypeptides and nucleic acids encoding PAD polypeptides described herein are available for use as antigens to generate the production of antibodies to be used in passive immunotherapy, to be used as diagnostic reagents and to be used as reagents in other processes such as affinity chromatography. According to a further related aspect, the invention also includes so-called "passive immunization" methods for preventing or treating PRRSV. For example, an antiserum comprising antibodies produced by immunizing a heterologous host with PRRSV or mutants thereof, or an immunogenic fragment thereof, is used for the therapeutic treatment of a pig infected with PRRSV. However, even vaccines that provide active immunity, ie, vaccines comprising PRRSV or mutants thereof, or immunogenic fragments thereof, have been shown in certain cases to be effective when administered as a treatment.

Therapeutic against either active immunity or passive immunity and the desired use of the vaccine and antiserum can be either prophylactic or therapeutic. According to this aspect of the invention, animal subjects, for example, pigs, are administered with an effective dose of an antibody that specifically binds to a PAD polypeptide, a derivative, a homolog or a variant or fragment thereof of the present invention. According to a related embodiment, these methods and compositions may include combinations of antibodies that bind to at least one or more PAD polypeptides. The antibodies can also be administered with a vehicle, as described herein. In general, according to this aspect of the invention, these antibodies, which will be administered (or formulated for administration) peritoneally, orally, intranasally, subcutaneously, intramuscularly, topically or intravenously, but can be administered or formulated for administration by any pharmaceutically effective route (ie, effective to produce the therapeutic levels indicated). In this way, among others, antibodies against PRRSV can be used to inhibit and / or treat PRRSV infections. The invention also relates to pharmaceutical diagnostic kits comprising one or more containers filled with one or more of the ingredients of the compositions of the invention mentioned above, for example, nucleic acids encoding a PAD polypeptide, a PAD polypeptide, a derivative, a homologue or a variant or fragment thereof, or an antibody directed toward a PAD polypeptide, a derivative, a homolog or a variant or fragment thereof or a vaccine that includes a PAD polypeptide, or a nucleic acid encoding a PAD polypeptide. Thus, the polynucleotides, polypeptide and antibodies, and vaccines of the present invention can be used as research reagents and materials for treatments and diagnostics for PRRSV. In particular, it is contemplated that the kits can be used to determine if a pig was successfully vaccinated in such a way that the antibodies directed towards PAD are present in the sample taken. For example, a biological sample from an animal, for example a pig, vaccinated with a PAD polypeptide described above is taken and incubated with a PAD polypeptide or other anti-PAD antibody preparation for a sufficient time for binding of the antibody. Binding of the antibody to the PAD polypeptide or other anti-PAD antibody preparation is detected using methods known to one of ordinary skill in the art, for example Western blot analysis and / or ELISA assays. The anti-PAD antibodies of the invention have various utilities For example, anti-PAD antibodies can be used in diagnostic assays for PRRSV, for example, detecting their expression in specific cells, tissues or serum. Various diagnostic assay techniques known in the art can be used, such as competitive binding assays, direct or indirect sandwich assays and immunoprecipitation assays carried out in either heterogeneous or homogeneous phases (Zola, Monoclona l An tibodies: A Manua l of Techniques, CRC Press, Inc. (1987) pp. 147-158). The antibodies used in the diagnostic assays can be labeled with a detectable portion. Detection of an antibody of the present invention can be facilitated by coupling (i.e., physical binding) of the antibody to a detectable portion. Examples of detectable portions include various enzymes, prosthetic groups, fluorescent materials, luminescent materials, bioluminescent materials and radioactive materials. Examples of suitable enzymes include horseradish peroxidase, alkaline phosphatase, beta-galactosidase or acetylcholinesterase; examples of suitable prostatic group complexes include streptavidin / biotin and avidin / biotin; examples of suitable fluorescent materials include umbellifer, fluorescein, fluorescein isothiocyanate, rhodamine, dichlorotriazinylamine fluorescein, dansyl chloride or phycoerythrin; an example of a luminescent material includes luminol; examples of bioluminescent materials include luciferase, luciferin and aequorin, and examples of a suitable radioactive material include I, 1, S or H. The detectable portion must be capable of producing, either directly or indirectly, a detectable signal. Any method known in the art for conjugating the antibody to the detectable portion can be employed, including those methods described by Hunter et al., Na ture, 144: 945 (1962); David et al., Biochemistry, 13: 1014 (1974); Pain et al., J. Immunol. Meth. , 40: 219 (1981) and Nygren, J. His toche. and Cytochem. , 30: 407 (1982). The present inventors contemplate that these diagnostic kits would be of value in eradication programs for PRRSV at various levels, including but not limited to an individual (farm), regional and / or national level. Anti-PAD antibodies are also useful for the purification of PAD affinity from a culture of recombinant cells or natural sources. In this process, antibodies against PAD are immobilized on a suitable support, such as a Sephadex resin or filter paper, using methods well known in the art. The immobilized antibody is then contacted with a sample containing the PAD that will be purified, and subsequently the support is washed with a suitable solvent that will remove substantially all the material in the sample except the PAD, which binds to the immobilized antibody. Finally, the support is washed with another suitable solvent that frees the PAD of the antibody. Although the invention has been described with reference to PAD polypeptides, it should be understood that this covers a derivative, a homolog or a variant or fragment thereof and similar proteins with additions, deletions or substitutions that do not substantially affect the protective antigenic properties of the protein recombinant. The vaccine composition containing the attenuated PRRSV of the invention is administered to a pig susceptible to or otherwise at risk of PRRSV infection to increase the pig's own immune response capabilities. This amount is defined as an "immunogenically effective dose". In this use, the precise amount depends again on the state of health and weight of the pig, the mode of administration, the nature of the formulation, etc. The vaccine compositions may additionally incorporate in additional substances to stabilize pH, or to function as adjuvants, wetting agents or emulsifying agents, which serve to improve the effectiveness of the vaccine. The vaccines are generally formulated for parenteral administration and injected either subcutaneously or intramuscularly. These vaccines can also be formulated as suppositories or for oral administration, using methods known in the art. The amount of vaccine sufficient to confer immunity against PRRSV is determined by methods well known to those skilled in the art. This amount will be determined based on the characteristics of the vaccine recipient and the level of immunity required. Typically, the amount of vaccine or dose to be administered will be determined based on the judgment of an expert veterinarian or can be easily determined by routine experimentation. The amount of virus vaccine of each strain can be adjusted, that is, increased or reduced, to result in a formulation that provides sufficient protection against infection with the desired PRRSV. The present inventors contemplate that different strains can be combined in any amount determined as effective to prevent or treat PRRSV infection of a strain in the vaccine formulation, and possibly other strains if cross protection occurs. Cross protection to infection by other strains of PRRSV may depend on the order in which the PRRSV strains are administered or whether the pig has been subjected to a PRRSV infection before as described above. According to the present invention, the different PRRSV or PAD or PRRSV of the invention, for example, PAD of GP5, M and / or GP5-M heterodimer with the same or variable glycosylation patterns in the ectodomain of GP5, they can be administered sequentially or progressively or alternatively they can be administered simultaneously in a mixture. Sequential or progressive administration of the vaccine compositions of the invention may be required to develop sufficient levels of immunity to multiple strains of PRRSV. Individual or multiple administration of the vaccine compositions of the invention can be carried out. Multiple administration may be required to develop sufficient levels of immunity. Induced levels of immunity can be monitored by measuring the amount of secretory and serum neutralizing antibodies, and the doses adjusted or the vaccines repeated as necessary to maintain the desired levels of protection. In one aspect of the immunization protocol against a PRRSV infection, a virus having a PAD of a GP5-M heterodimer of PRRSV of the present invention with glycosylation at position 44 of GP5 in the North American strain is administered, followed by administration of a virus having a PAD of a GP5-M heterodimer of PRRSV of the present invention without glycosylation at position 44 of GP5 in a North American strain, and then attacking with a PRRSV having glycosylation in the neutralizing epitope of GP5. In another aspect, a virus having a PAD of a GP5-M heterodimer of PRRSV of the present invention with glycosylation at position 46 in GP5 in the European strain is administered, followed by the administration of a virus having a PAD of a GP5-M heterodimer of PRRSV of the present invention without glycosylation at position 46 in GP5 in the European strain, and then it is attacked with a PRRSV that has glycosylation in the neutralizing epitope of GP5. In one aspect of the immunization protocol against a PRRSV infection, a PAD comprising a GP5-M heterodimer of PRRSV of the present invention with glycosylation at position 44 of GP5 in a North American strain is administered, followed by the administration of a PAD comprising a GP5-M heterodimer of PRRSV of the present invention without glycosylation at position 44 of GP5 in a North American strain, and then attacking with a PRRSV strain having glycosylation in the neutralizing epitope of GP5. In another aspect, a PAD comprising a GP5-M heterodimer of PRRSV of the present invention with glycosylation at position 46 of a GP5 in a European strain is administered, followed by the administration of a PAD comprising a GP5-M heterodimer of PRRSV of the present invention without glycosylation at position 46 of GP5 in a European strain, and then attacked with a PRRSV strain having glycosylation in the neutralizing epitope of GP5. In one embodiment of the invention, a GP5 PAD may not have amino acid glycans 1-35 in the protein GP5 of NA PRRSV. In another aspect, a PAD of GP5 can have a glucan at position 44 in the GP5 protein of NA PRRSV. In another aspect, a PAD of GP5 can have a glucan at position 44 in GP5 of NA PRRSV and can have glycans present or absent in amino acids 1-35 in the GP5 protein of NA PRRSV, for example, as found in some strains of NA PRRSV. In one embodiment of the invention, a GP5-M heterodimer PAD may not have glucans of amino acids 1-35 in the GP5 protein of NA PRRSV. In another aspect, a GP5-M heterodimer PAD can have a glucan at position 44 in the GP5 protein of NA PRRSV. In another aspect, a GP5-M heterodimer PAD can have a glucan at position 44 in the GP5 of NA PRRSV and have glycans present or absent in amino acids 1-35 in the GP5 protein of NA PRRSV, for example, as found in some strains of NA PRRSV. In one embodiment of the invention, a GPS PAD may not have glucans of amino acids 1-37 in the GP5 protein of EU PRRSV, as found in Lelystad. In another aspect, a PAD of GP5 can have a glucan at position 46 in the GP5 protein of EU PRRSV. In another aspect, a PAD of GP5 can have a glucan at position 46 in GP5 of EU PRRSV and have glucans present or absent in amino acids 1-37 in GP5 of EU PRRS, for example, as found in some strains of EU PRRSV. In one embodiment of the invention, a GP5-M heterodimer PAD may not have glucans of amino acids 1-37 in the GP5 protein of EU PRRSV, as found in Lelystad. In another aspect, a GP5-M heterodimer PAD can have a glucan at position 46 in the GP5 protein of EU PRRSV. In another aspect, a GP5-M heterodimer PAD can have a glucan at position 46 in the GP5 of EU PRRSV and have glucans present or absent in amino acids 1-37 in the GP5 protein of EU PRRSV, for example, as found in some strains of EU PRRSV.

Examples Example 1 The solution for the identification of the PAD of PRRSV was not obvious because others have not synthesized the information that refers to the North American and European strains of PRRSV and Equine Arteritis Virus (EAV) in knowledge. For example, the modified live vaccine (MLV) for EAV is very effective while the MLV for PRRSV is not. Thus, many scientists have apparently concluded that a comparison of the similarities and differences between the two viruses would not be of value with respect to the development of a PRRSV vaccine. At the beginning of the beginning of February 2005, the inventors studied numerous publications, synthesized The different important information and by deductive reasoning identified the protective antigenic determinants of PRRSV as the heterodimer matrix-glycoprotein 5 (M-GP5). One of the most interesting aspects of PRRS epidemiology is the variation between North American and European isolates and the fact that PRRS was a relatively mild disease at least prior to the introduction of a live PRRSV vaccine in Europe of the United States. in Western Europe. In addition, in some small traditional American farms, PRRSV disappears spontaneously for no apparent reason. While in the United States, PRRS has always caused more devastating economic losses (especially in large herds). For this reason the inventors compared N-glycosylation sites in VR2332 (the common North American strain) and Lelystad virus (the common North American strain) and Lelystad virus (the common European strain). See table 1. Please note that the similarity of HLV013 and Lelystad viruses; however, these 2 viruses are not identical because the signal sequence of GP5 and the hypervariable regions of GP5 are very different. According to publications, there is evidence that live Lelystad virus can protect pigs against PRRS to a higher degree than VR 2332. Lack of glycosylation at amino acid 1-43 is the reason that PRS has been less severe in parts of Europe and some farms in the United States. That is, the Lelystad virus has been naturally immunizing in pigs in Europe and strains similar to HLV013 have been doing the same on a limited number of farms in the United States. The fact that the North American strains VR2332 and Mnl84 are quite different with respect to glycosylation led us to compare the antibody reactivity of strains of VR2332 and Lelystad (Table 2). Since the Lelystad virus antibody reacts with the GP5-M heterodimer of Lelystad, the hypothesis was created that the GP5-M heterodimer contains the protective antigenic determinants of PRRSV and could be the basis for resistance to PRRS.

Table 1 Comparison of amino acid sequence and N-glycosylation of several strains of PRRSV * Ingelvac MLV, Ingelvac ATP and PrimePac MLV all similar to VR2332.

The inventors were aware that the MLV vaccine for EAV was quite effective. Therefore, the inventors compared the different immunological and genomic aspects of PRRSV for EAV (Table 3).

Table 2 Comparison of antibody reactivity of strains of VR2332 and Leystad by Western blot *? indicates that the result has not been published ** Positive by peptide ELISA Table 3 Comparison of PRRSV and VAS with respect to deducting protective antigenic determinants of PRRSV * The horse seems not to respond to the EAV nucleocapsid; males that carry the virus in their testicles may have antibodies against N. ** It has not been published + Since EAV does not have N-glycosylation sites to the left of the conserved VN epitope, the GP5-M heterodimer It contains the protective antigenic determinants of PRRS by deductive reasoning. -Note that GP5 in PRRSV is synonymous with GL capsid protein in EAV. Through synthesis and deduction, the identification of antigenic protective determinants (PAD) were identified. The PAD of PRRSV are the antigens associated with the GP5-M heterodimer and thus the basis of this description. Plagemann, Faaberg and Osorio have focused simply on the virus neutralizing (VN) aspects of PRRSV associated with GP5 protein. However, the antibodies are not simply virus neutralizers, thus in the protection against PRRSV, the antibodies interfere with the heparin receptor in the matrix protein and the sialic acid component of GP5 which prevents the fixation and entry into the macrophages. Alveolar pigs (table 3). The concept of inhibition of antibodies in this description is not virus neutralization per se. In summary, • Lelystad and HLV013 strains of PRRSV do not have glucans in amino acid residues (AA) 1-43 (in the signal sequence or the hypervariable reaction towards the 5 'end of the conserved neutralizing epitope) • Antibodies against viruses Viruses and PRRSV vaccines do not react with the GP5-M heterodimer of all PRRSV isolates due to the presence of glucans in the amino acids 1-43 • The glucans in amino acids 1-43 of PRRSV in GP5 are the decoy A epitope (Osorio) and the excess glycans (Plagemann) but these workers believe that decoy glycans only interfere with the production of neutralizing antibodies of virus (VN) against the region conserved in GP5 (they do not mention the importance of the matrix protein). • In fact, decoy glycans interfere with the production of antibodies against the GP5-M heterodimer more than just interference with the production of VN against GP5 antibodies. The antibodies against GP5-M heterodimer prevent the binding and entry of PRRSV into porcine alveolar macrophages (not only in the neutralization of the virus). Antibodies are only induced by living PRRSV if amino acids 1-43 are free of glucans and in this way the reason why the current MLV PRRSV vaccines are not effective. Researchers of PRRSV have focused on classical approaches to develop vaccines against viruses that include mechanisms associated with either cell-mediated immunity (CMI) and / or virus neutralizing antibodies (VN).

Plagemann, Faaberg, and Osorio have identified an epitope conserved in GP5 that is associated with VN antibodies. However, antibodies against conserved GP5 epitope alone they do not induce sufficient protective antibodies against PRRSV. Plagemann and Faaberg have suggested that glucans in GP5 could interfere with the production of VN antibodies and Osorio has suggested that the decoy epitope prevents the production of VN antibodies. Osorio has injected sows with serum containing VN antibodies and protected their piglets against PRRSV; however, when the piglets were injected with the antibody preparation, they were not protected. The young pigs were not protected because the Osorio antiserum lacked a complete set of antibodies against PAD (All viruses used by Osorio to induce VN antibodies contained glucans in amino acids 1-43 of GP5). In this way, the antibodies against PAD are very different than the VN antibodies directed towards the GP5 protein alone. Murtaugh has evidence that VN antibodies are not involved in the elimination of the virus in naturally affected pigs and favors a mechanism involving CMI. Murtaugh said at a recent meeting in Toronto (March 5, 2005) that the protective determinants of PRRSV have not been described. Publications by these experts and others in research PRRSV (attached) they have repeatedly indicated that PRRSV is a unique virus that causes some resistance to homologous virus and very little protection to attack heterologous virus and responses to CMI and VN are slow develop and are not necessarily developed with resistance to the virus. What has not been obvious to other scientists is that PAD is a combination of the conserved region of the GP5 protein bound to the matrix in a heterodimer form. In addition, the GP5 protein should not contain N-glycosylated asparagine between amino acids 1-43. It has been reported that the matrix protein (heparin receptor) is involved in virus binding to porcine alveolar macrophages (PAM) pig and GP5 protein containing sialic acid residues allowing entry to PAM. Thus, antibodies against PAD (GP5-M heterodimer) prevent PRRSV binding and entry instead of only carrying out virus neutralization. Currently available vaccines do not produce antibodies against PAD of PRRSV.

Example 2 Recent work in our laboratory showed that a live strain of PRRSV (Figure 2, strain HLV013) lacking glycan before amino acid 44 of GP5 could induce high titers of neutralizing epitope GP as determined by an ELISA assay neutralizing peptides . Further analysis of HLV013 by Western immuno response indicated earlier, strong antibody heterodimer GP5 and GP5-M when compared with VR2332 and sera from infected pigs showed HLV013 cross-reaction with strain IA97-7895 of PRRSV than sera from pigs infected with VR2332 (figures 2 and 3). The results of these studies have led us to believe that the N-glycosylation patterns in association with the GP5-M heterodimer are important components of a more effective neutralizing antibody response. The influence of glycosylation on the evolution of neutralizing antibodies was first shown in this experiment. In this experiment, three groups of six pigs to PRRSV negative treated as shown in Table A. The pigs were inoculated on day 0 and again on day 28 followed by inoculation with a strain heterologous day 90. Serum was taken during the course of the study and tested for neutralizing antibodies against the inoculating and heterologous strains (figure 4).

Table A Design of the pig inoculation test 1 This test provides evidence that there is a large difference between protective antibody responses to strains that differ in glycosylation. See Figure 5. HLV013 lacking glucans before amino acid 44 had a faster and more robust antibody response before attack with an additional cross-reactivity when compared to VR2332. Pigs after challenge inoculated with HLV013 had a faster anamnestic response and faster response time to generate antibodies against the attack strain. The following table corresponds to the Western blot of figure 5.

Each row contains 10 ug of purified PRRSV.

Primary antibodies were diluted 1: 100 and the secondary antibody was diluted 1: 2000.

Example 3 Inoculation of animals Two pigs of 2-3 weeks of age were obtained from a source with no detectable presence of PRRSV and housed in the ISU research facilities. After acclimation, the pigs were infected intranasally with 105-TC-ID50 of the desired strain. The pigs were bled on days -7, 0, 7, 21, 35 and 70 after inoculation to allow adequate time for the production of neutralizing antibodies followed by human euthanasia. The sera were aliquoted and sent to ISU Diagnostic Lab for ELISA anti-N antibodies (Herdcheck, IDEXX), SDSU Diagnostic Lab for MARC 145 serum neutralization assay (FFN) and the University of Minnesota for neutralizing ELISA peptides (Plagemann). The remaining sera were used for testing for AM infection in ISU. This experiment was carried out to further evaluate the ability of N5-glucan-deficient strains of GP5 to generate high titers of neutralizing antibodies and their cross-reactivity. PRRSV negative pigs were obtained and randomized into three groups as shown in table B. At the conclusion of the test, serum was taken from all pigs and tested for virus-neutralizing antibodies against a variety of different strains of PRRSV 'table c Table B All doses of PRRSV were 1 ml given 1M at a dose of 1 x 106 TCID50 / ml NA = not applicable Table C Neutralizing antibody titers (geometric means) against several strains of PRRSV Although all 3 groups generated homologous and heterologous neutralizing titers, group 2 had clearly higher titers. The addition of a third type of glucan in group 3 did not increase the antibody response beyond what was demonstrated in group 2. This indicates that the combination of HLV013 and HLV093 is very suitable for a universal vaccine to develop neutralizing antibodies heterologous The effect of the glucan shield can be further demonstrated by comparing geometric means of the geometric mean against groups of strains with the same number of N-glycans before amino acid 44. The 7 different strains used in the FFN trial were divided into 3 different groups based on the type of glucan; NA-0, NA-1 and NA-2. One would expect to see the highest titers against the NA-0 strains and the lowest against the NA-2 strains notwithstanding the sequence homology of GP5. This is in fact what was observed as shown in Figure 6. This ability to predict the cross-reaction of protective antibodies supports the use of glycan typing to define heterology among strains of PRRSV.

Example 4 Alveolar macrophage uptake AMs will be taken for culture as previously described (Mengeling, Thacker). Pigs (4-6 weeks of age) will be anesthetized and euthanized by exsanguination. The lungs will be removed from the chest cavity for lung lavage. The washing fluid shall consist of medium Modified Dulbecco's Eagle (DMEM) supplemented with gentamicin (0.5 mg / ml), penicillin (25 U / ml), streptomycin (25 μg / ml), polymyxin B sulfate (3 U / ml), and amphotericin B (25 μg / ml). The washing fluid will be discarded and aspirated several times to collect the AMs. It is expected to collect 100-200 ml of wash fluid per pig by grouping the aspirated fluid from individual pigs. The fluid of different pigs will not be mixed to avoid immune reactions and to identify any difference in the susceptibility of AM to PRRSV. The harvested fluid will be centrifuged 1, 000 g for 15 minutes, resuspended in 50 ml of PBS and washed twice more. The AMs will be counted and resuspended in PBS at a concentration of approximately 5 x 10 7 AMs / 1.5 ml followed by storage in liquid nitrogen. The lots will be validated by infecting AMs with the VR2332 strain of PRRSV and carrying out an immunoperoxidase monolayer assay.

(IPMA) with known positive and negative sera to determine the TCID50.

Example 5 Effect of antibody inhibition of infection of alveolar macrophages Polyclonal or monoclonal antibodies will be diluted 2 times and added to 105 TCID50 of several homologous and heterologous PRRSV strains. The mixtures will be inoculated for 1 hour at 37 ° C and then inoculated on alveolar macrophages (AMs) seeded in 96-well culture plates. The cells will be incubated for 1 hour at 37 ° C with 5% C02, washed and incubated again until 10 hours after inoculation (Delputte). The cells will be fixed and the percentage of infected cells will be calculated based on staining with immunoperoxidase. The t test will be used to compare the percentage of infected cells between treatment and control wells.

Example 6 Immunoperoxidase monolayer assay. IMPA will be used to determine the percentage of infected cells as described by Delputte et al. Briefly, fixed cells will be incubated for 1 hour at 37 ° C with anti-nucleocapsid monoclonal antibody and diluted 1/100 in PBS with 10% goat serum, followed by incubation for one hour at 37 ° C with Ig anti-mouse IgG. goat marked with peroxidase. The infected cells will be visualized by a substrate solution of 3-amino-9-ethylcarbazole in 0.05 M acetate pH buffer (pH 5) with 0.05% H202. The reaction will be blocked when washing with acetate pH regulator. Viral positive cells and total cells will be counted by light microscopy to determine the percentage of infected cells.

Example 7 Dodecyl sodium polyacrylamide sulfate gel electrophoresis (SDS-PAGE) An equal volume of antigen will be mixed with 2x LDS charge buffer (Invitrogen) which includes either reducing agent or no reducing agent. All samples will be boiled for 5 minutes. Using 4-12% of Novex Un-PAGE pre-processed gradient gels (Invitrogen) and an XCell SureLock mini-cell (Invitrogen), 15 μl of each sample will be loaded into their respective wells. A pre-stained ladder with SeeBlue Plus2 will be loaded in the first and last wells at a volume of 10 μl. Once the gel is charged and both the pH regulator core and the lower pH regulator chamber are filled with lx MES pH regulator (Invitrogen), the power supply current is set at 200 V and Let it run for 45 minutes.

Example 8 Western Immunosorption Western blots will be used to further analyze and identify protective epitopes. Four absorption pads will be immersed in transfer pH regulator, which consists of 25 mM of Bis-Tris, 25 mM of Vicien, 1 mM of ethylenediaminetetraacetic acid (EDTA) with % methanol. The polyvinylidene fluoride (PVDF) will be briefly immersed in methanol and then placed in the transfer pH buffer. Two sheets of absorbent filter paper will be immersed in transfer pH regulator. All are set at 4 ° C with remaining pH transfer buffer until the gel is finished. Once the SDS-PAGE is complete, the gel cassette is removed and opened. After loading absorption materials, the absorption module is filled with transfer pH regulator and the pH regulator chamber is filled with purified Nano water. The current will be set at 170 mA and 30 V and will be allowed to run for 75 minutes. The membrane will be removed from the absorption sandwich and transferred to a tray and covered in blocking pH regulator, washed ELISA with fish gelatin (1.5 mM KH2P04, 20 mM Na2HP04, 134 mM NaCl, 2.7 mM KCl, 0.05 % of T een-20 with 0.25% fish gelatin). The membrane will be left in the blocking pH regulator overnight at 4 ° C. A 1: 4000 dilution of pig serum will be made in 20 ml of blocking buffer. The blocking pH regulator will be poured out and the pig serum dilution is added and allowed to oscillate at room temperature for 60 minutes. The dilution of pig serum will be poured and the membrane will be washed in 20 ml of ELISA wash for 10 minutes, oscillating at room temperature. The washing will be poured and the stages of washing will be repeated twice for a total of three washes. During the last wash step, the goat anti-goat IgG conjugated to biotin SP (Jackson Immuno Research) will be diluted 1: 2000 in 20 ml of blocking buffer. After the final wash, the anti-goat serum dilution will be poured on the membrane and it will be left to oscillate at room temperature for 60 minutes. Three stages of washing will be repeated as described above. A 1: 2000 dilution of streptavidin Hrp (Zymed) in 20 ml of blocking buffer is prepared and poured onto the PVDF membrane, oscillating at room temperature for 60 minutes. Three washing steps are repeated again. During 1 final wash step, TMB Membrane Peroxidase Substrate (KPL) System will be prepared by mixing in a small tray 12.5 ml of TMB peroxidase substance, 12.5 ml of peroxidase B solution and 2.5 ml of TMB membrane enhancer. Once the wash is completed, the liquid is poured and the membrane is immersed in the substrate for 1 minute or until the desired horseradish peroxidase color is achieved without an intense background. The PVDF membrane will be dried and covered in transparent and scanned plastic for the electronic registration of Western blot.

Example 9 Real-time quantitative real-time quantitative PCR (qRT-PCR) will be used as another method to compare the ability of antibodies to prevent binding of infection and infection of AMs. After infection and incubation of AM with antibody and PRRSV as described above, the cells will be washed three times to remove unbound extracellular virus and antibody-virus complexes. The AMs will be harvested, lysates and the viral RNA extracted using the Qiagen Virus Spin kit. The extract will then be assayed by qRT-PCR (Tetracore) in the Bio-Rad iCycler iQ and compared with a standard curve. Cyclization conditions will be as follows: 1) RT stage: 52 ° C for 1,800 seconds, 2) activation step with enzyme: 95 ° C for 900 seconds, 3) 3 stages of PCR: 40 cycles (changed from 50 recommended cycles by Tetracore) of (94 ° C for 30 seconds, 61 ° C for 60 seconds and 72 ° C for 60 seconds).

Example 10 Production of PRRSV antibodies in pigs Twenty conventional PRRSV-free pigs of 5 a 6 weeks of age will be injected with a PRRSV PAD vaccine. The serum of each pig will be evaluated weekly for antibodies against PRRSV detectable by ELISA, and Inhibition of infection of alveolar macrophages (Erdman). Pigs will be repeatedly injected occasionally and weekly if adequate levels of antibodies are not obtained. It is anticipated that the pigs will be slaughtered and their blood taken for serum pooled 6 to 12 weeks after exposure. Twenty pigs of the same age will serve as uninfected controls and will be the source of normal pig serum.

Example 11 Production of PRRSV antibodies in horses Two horses will receive PAD polypeptide mixed in incomplete Freund's adjuvant by intramuscular injection followed by CVA only at weekly intervals for 8 weeks. Horse serum will be evaluated by inhibition of alveolar macrophage infection and Western blot analysis. Serum from normal horses will be collected by peptide sampling before immunization with CVA.

Example 12 Concentration of antibodies against PAD of PRRSV Plasma containing antibodies against PRRSV will be concentrated by the removal of lipids and albumin by precipitation and subsequent ultrafiltration up to 90% of globulin content.

Example 13 Attack model for evaluation of antibodies for protection against PRRSV Pigs derived by hysterectomy and deprived of colostrum (HDCD) will be procured from the Rexanne Struve Laboratory at 4-6 hours of age. The pigs will be fed a milk replacement diet Esbilac. The milk replacement of pigs in the main groups will be supplemented with PRRSV PAD antibodies that contain either pig or horse globulin. The control pigs will receive normal porcine or equine globulin of the same concentration as the pigs in the main groups. Esbilac that contains globulin will not be fed after 36 hours of age. All pigs will be attacked intranasally with the HLV092 strain of PRRSV at 3 days of age. Each test preparation or combination will be evaluated in 10 HDCD pigs which will be attacked simultaneously with 10 control pigs. One half of the pigs will be slaughtered and necropsied 14 days after the attack and the tissues (blood, lung, lymph nodes, angina) will be excised and tested for the presence of PRRSV by qPCR and virus isolation. The sentinela pigs will be put with half of the remaining pigs in each group to determine if the attacked pigs are capable of transmitting the virus during the next 2-week time period.

EXAMPLE 14 PRRSV positive farm field experiment A PRRSV positive farm will be selected with the following approximate mortality rates - 15-20% hatching and 10-15% hatchery. The pigs within each bait will be randomly assigned to 2 groups. Normal concentrated globulin (NG-group 1) and PRRSV antibody concentrate generated against PAD (group 2) will be administered orally before 24 hours of age and subsequently by intraperitoneal injection based on half-life determinations in the ISU experiments. The total number of pigs per group will be based on the number of pigs required to prove a reduction in the mortality rate of 10% in both calving and hatchery. Statistical software (JMP 5.1.2, SAS Institute, Inc., Cary, N.C.) was used to determine the sample size to compare proportions of two independent groups. At a power of 90%, 672 animals (336 per group) would be required to detect a 10% difference in mortality (from 20% to 10%) at the significance level of p < .05. To detect a difference of 10% in mortality (from 15% to 5%) at the same power and level p, 536 animals (268 per group) are required. The cause of death will be determined by complete necropsy and the presentation of samples for qPCR.

Example 15 Statistical analysis The collected quantitative data (virus titre, qPCR, antibody titers) will be analyzed using ANOVA. The square chi test for proportions will be used for categorical data (mortality rate,% pulmonary involvement, presence or absence of PRRSV). The analysis will be carried out using SAS statistical software and the significance will be established at p < 0.05.

Example 16 Laboratory support data and studies in pigs Table 4 FFN data Neutralization of the virus was tested on cells Marc 145. The values indicate the reciprocal of the highest serum dilution exhibiting activity in neutralization. Pigs (n = 6 per group) were inoculated on day 0 with a false control, HLV013 or VR2332 PRRSV strains. On day 14, the pigs of group HLV013 were reinforced (vaccine reinforcement) with HLV093. On day 42 dpi, only the HLV013 group showed VN activity. All groups were attacked with HLV092 on day 90. The VN activity of group HLV013 continued to increase when tested against homologous and heterologous viruses.

* Days after inoculation ** Days after attack *** Not determined Pigs were injected with inactivated crude viral antigen comprising GP5, M and GP5-M heterodimer prepared from HLV013 and the ELISA response was compared (Figure 15) with that of the pigs injected with a commercial inactivated PRRS vaccine (Intervet). HLV013 induced rapid and high antibody titers compared to the commercial vaccine. An attack study was carried out in which HLV013 and VR2332 live were inoculated in experimental pigs and subsequently attacked with a heterologous strain (HLV092 or PRRSV (Table 6).) The results indicate that protection was induced by both viruses, however, the resistance appeared to be induced more rapidly by HLV013. In experiment 1, strain HLV 093 was detected in group HLV013 28 days after inoculation with HLV013.A live immunization method with PRRSV is as follows: Stage 1 - inject pigs with live HLV013 (figure 10) on day 1 Stage 2 - inject pigs with live HLV093 (figure 11) on day 21 Stage 3 - inject pigs with live HLV092 (figure 12) on day 42 The pigs immunized in these progressive stages will produce bodies against all the protective components of PAD and thus heterologous protection against most if not all preponderant isolates of PRRSV in North America. Injecting animals with HLV092 first will not result in heterologous protection. For protection against European isolates, a similar scheme may be required but using isolates of the European glycan types, for example, by initiating or administering a European PRRSV strain having little or no glycosylation between amino acids 31-39 of the GP5 ectodomain. By example, the injection of pigs with LV does not induce antibodies against the GP5 protein of VR2332 but it does induce antibodies against GP5 and the GP5-M heterodimer of LV.

Table 7 Glucan typing scheme developed by the inventors In accordance with the present invention, PRRSV strains within the North American and European genotypes are grouped based on their glycosylation patterns. This discovery is referred to by the inventors as a glycan typing scheme. Glucan typing is a more accurate means of detecting heterologous PRRSV strains as new strains in the population than sequence homology of ORF5. The present inventors contemplate that the discernment of glycosylation patterns can be used in individual or multivalent vaccines or in the development of vaccination schedules and protocols. a - NA = North American, EU = European b - Number of glucans located in the GP5 ectodomain excluding highly conserved glycans located at amino acid 44 to 51 for strains NA and amino acids 46 and 53 for strains EU. When these glucans are absent they should be indicated as follows: if an NA-1 strain lacks a glucan at amino acid 44 it is described with NA-1 (? 44). c - as the number of predicted glucans increases, resistance to inducing protective (neutralizing) antibodies and / or susceptibility to these antibodies also increases. d - NA-0 and EU-0 are predicted to be the progenitor strains for all North American and European strains respectively. Thus, these viruses must be included in attempts to generate cross-reactive antibodies. After NA-0 and EU-0, glucan typing can be a predictor of heterology that is currently poorly defined for PRRSV. * This scheme may be applicable to other RNA viruses. Table 7a FFN data from pigs inoculated with HLV013 (two logarithms higher than in table 5). Blood was taken 42 days after the inoculation. Neutralization of the virus was tested on Marc 145 cells. Values indicate the reciprocal of the highest serum dilution exhibiting neutralization activity.

Table 8 Attack data with virulent PRRSV (HLV092) from pigs described in figure 16 and tables 6-7 a Number of pigs with lung score of interstitial pneumonia (IP) > 2 on a scale of 1 to 6. b Number of pigs with either mild, moderate, or servera peribronchiolar lymphoid hyperplasia (PLH) based on histopathology. c Quantitative PCR (average viral copies per ml) of serum 10 days after the attack.

Table 9 Sequencing of ORF 5 of PRRSV. The nucleotide sequences were translated into the amino acid sequences1 and the N-glycosylation sites were predicted2. Only the first 80 amino acids are shown, however the genotypic kinship (percentage homology) is based on the complete sequence (200 amino acids). Potential N-glycosylation sites are underlined.

Identical Genotypes ExPASy-Translate Tool http: // us. expasy org / tools / dna. html 2 NetNGlyc 1.0 Server http: //cbs.dtu.dk/services/NetNGlyc/ DEPOSITS A deposit of HLV013, HLV092, HLV093 and N184 viruses is and will be maintained by Dr. Delbert Harris, Room 45, Kildee Hall, Io a State University, Ames, Iowa 50011, prior to the filing date of this request. Access to this deposit will be available during the pending status of the application to the Patent and Trademark Commissioner and persons determined by the Commissioner will be entitled to them after an application. After allowing any claim to the application, the applicants will make available to the public without restriction a deposit of at least 25 frozen or lyophilized samples (1 ml each) of the HLV013, HLV092, HLV093, HLV094 and MN184 viruses in the American Collection of Types of Crops (ATCC), Manassas, Virginia 201110. The 25 freeze-dried or freeze-dried samples (each containing 1 ml) of PRRSV viruses of HLV013, HLV092, HLV093, HLV094 and MN184 deposited with the ATCC will be taken from the same deposit preserved in Room 45, Kildee Hall, Io a State University and described above. In addition, applicants will meet all the requirements of 37 C.F.R. § 1.801-1.809, including providing an indication of the viability of the sample when it is deposit. This deposit of 25 frozen or lyophilized samples (each 1 ml) of HLV013, HLV092, HLV093, HLV094 and MN184 viruses will be preserved without restriction in the ATCC deposit, which is a public deposit, for a period of 30 years, or 5 years after the most recent application, or during the life of the patent, whichever is longer, and will be replaced if it were to Go back not viable during that period. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (55)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. Use of a first GP5-M heterodimer, wherein GP5 has glycosylation at position 44 of GP5 of a North American PRRSV strain (NA) or glycosylation at position 46 of GP5 in a European PRRSV strain (EU); and use of a second GP5-M heterodimer, wherein the GP5 of the second GP5-M heterodimer has no glycosylation at position 44 of GP5 in a North American PRRSV strain (NA) or in position 46 in GP5 of a strain of European PRRSV

(EU), to immunize a pig against an infection with porcine reproductive and respiratory syndrome virus (PRRSV). 2. Use according to claim 1, wherein the first or second GP5-M heterodimer is delivered in a virus or a vector.

3. Use according to claim 2, wherein the virus is PRRSV, equine arteritis virus (EAV), lactate dehydrogenase elevation virus (LDV) or simian hemorrhagic fever virus (SHFV).

4. Use according to claim 2, wherein the first GP5-M heterodimer is supplied by a PRRSV of HLV013.

5. Use according to claim 1, characterized in that the second G, P5 has glycans present or absent in the ectodomain in the GP5 protein of NA PRRSV or in the GP5 protein of EU RRRSV.

6. Use according to claim 2, wherein the second GP5-M heterodimer is supplied by a PRRSV of HLV093.

7. Use or in accordance with claim 1, wherein the pig is attacked with a PRRSV causing PRRS.

8. Use according to claim 1, wherein the immunization protocol provides heterologous reactivity.

9. Use according to claim 1, wherein the first or second GP5-M heterodimer is an inactivated, live attenuated, subunit, recombinant or DNA vaccine.

10. Use according to claim 1, wherein the first or second GP5-M heterodimer is administered oronasally.

11. Use of the first GP5-M heterodimer, wherein the GP5 of the first heterodimer has glycosylation in the ectodomain of GP5 in a North American PRRSV strain (NA), or glycosylation in the ectodomain of GP5 in a European PRRSV strain ( EU); and use of a second GP5- heterodimer M, wherein the GP5 of the second GP5-M heterodimer has no glycosylation in the ectodomain of GP5 in a North American PRRSV strain (NA) or in the ectodomain in GP5 of a European PRRSV strain (EU), for manufacturing of a composition for immunizing a pig against an infection by the porcine reproductive and respiratory syndrome virus (PRRSV).

12. A method for identifying GP5-M heterodimers that develop protection against PRRSV, characterized in that it comprises: administering to a test pig a first GP5-M heterodimer, where GP5 has glycosylation at position 44 of GP5 of a virus of the North American porcine reproductive and respiratory syndrome (NA) (PRRSV) or glycosylation at position 46 of GP5 of a European PRRSV (EU) and administer to the test pig a second GP5-M heterodimer, where the GP5 of the second GP5- heterodimer M has no glycosylation at position 44 of GP5 of an American PRRSV (NA) or at position 46 of GP5 of a European PRRSV (EU); attacking the test pig to which the first and second GP5-M heterodimers were administered, and a control pig that was not administered the first and second GP5-M heterodimers with an infectious amount of a virus causing PRRS and determining if the first and second administered GP5-M heterodimers are effective to protect against the PRRSV attack.

13. The method according to claim 12, characterized in that the step of determining whether the first and second administered GP5-M heterodimers are effective to protect against the PRRSV attack comprises the step of: observing a change in the symptoms of PRRS, wherein administration of the first and second GP5-M heterodimers results in a reduction in the clinical signs or symptoms of PRRS comprising weight loss, reduced weight gain, lethargy, respiratory distress, "tachycardia" (forced expiration), Fevers, rough coats, sneezing, coughing, ocular edema, conjunctivitis, microscopic lung lesions due to large lesions, myocarditis, lymphadenitis, encephalitis and rhinitis compared with the control pig, indicates that the first and second administered GP5-M heterodimers are effective for protect against PRRS, while increasing the clinical signs or symptoms of PRRS that comprise any of the following: weight loss, reduced weight gain, lethargy, respiratory distress, "tachycardia" (forced expiration), fevers, coats harsh, sneezing, cough, ocular edema, conjunctivitis, microscopic lung lesions due to large lesions, myocarditis, lymphadenitis, encephalitis and rhinitis compared to the control pig, indicates that the first and second administered GP5-M heterodimers are not effective in protecting against PRRS.

14. The method according to claim 12, characterized in that the step of determining whether the first and second administered GP5-M heterodimers are effective to protect against the attack PRRSV, comprises determining the presence or absence of attack PRRSV in the test pig by electron microscopy, fluorescent focus neutralization test (FFN) or Western blot assay, where the presence of the PRRSV attack indicates that the first and second administered GP5-M heterodimers are not effective to protect against PRRS and the absence of PRRSV of attack indicates that the first and second GP5-M heterodimers administered are effective to protect against PRRS. 15. The method according to claim 12, characterized in that the first or second heterodimer

GP5-M is delivered in a virus or a vector.

16. The method according to claim 15, characterized in that the virus is PRRSV, equine arteritis virus (EAV), lactate dehydrogenase elevation virus (LDV), or simian hemorrhagic fever virus (SHFV).

17. The method according to claim 15, characterized in that the first GP5-M heterodimer is supplied by a PRRSV of HLV013.

18. The method of compliance with the claim 12, characterized in that the second GP5 has glycans present or absent in the ectodomain in the GP5 protein in the GP5 protein of EU PRRSV in strains of PRRSV NA or EU.

19. The method according to claim 15, characterized in that the second GP5-M heterodimer is supplied by a PRRSV of HLV093.

20. The method according to claim 12, characterized in that the first and second GP5-M heterodimers provide heterologous reactivity.

21. The method according to the claim 12, characterized in that the first or second heterodimer GP5-M is an inactivated, live attenuated, subunit, recombinant or DNA vaccine.

22. The method according to claim 12, characterized in that the first or second heterodimer GP5-M is administered oronasally.

23. An isolated polypeptide useful for generating a protective effect against PRRS, characterized in that it comprises: a sequence comprising a heterodimer of a matrix protein (protein M) of porcine reproductive and respiratory syndrome virus (PRRSV) and a glycoprotein 5 (GP5) ) of PRRSV, where the GP5 protein has N-glycosylation of amino acids asparagine located at position 44 of the GP5 protein in the North American PRRSV strains or in position 46 of the GP5 protein in the PRRSV strains European

24. The isolated polypeptide according to claim 23, characterized in that the PRRSV M protein and the PRRSV GP5, wherein the GP5 protein is linked to the M protein by a disulfide bond, wherein the disulfide bond results from the binding between a cysteine amino acid in the M protein located in position 9 in North American PRRSV strains or in position 8 in strains of EU PRRSV with a cysteine amino acid at position 48 of the GP5 protein in North American PRRSV strains or in the position 50 of European PRRSV strains, thus producing a GP5-M heterodimer.

25. An isolated polypeptide useful for generating a protective effect against PRRS, characterized in that it comprises: a sequence comprising a heterodimer of a porcine reproductive and respiratory syndrome virus protein (M protein) heterodimer (PRRSV) and a glycoprotein 5 (GP5) ) of PRRSV, wherein the GP5 protein does not have N-glycosylation of amino acids asparagine located at position 44 of the GP5 protein in North American PRRSV strains or in positions 46 of the GP5 protein of the European PRRSV strains.

26. The isolated polypeptide according to claim 25, characterized in that the PRRSV M protein and the PRRSV GP5, where the GP5 protein is linked to the M protein by a disulfide bond, wherein the disulfide bond results from the binding between a cysteine amino acid in the M protein located at position 9 in the North American PRRSV strains or in position 8 in the EU PRRSV strains with an amino acid cysteine at position 48 of GP5 protein in North American PRRSV strains or in position 50 of European PRRSV strains, thus producing a GP5-M heterodimer.

27. Use of a first GP5-M heterodimer, where GP5 has glycosylation at position 44 of GP5 in a American PRRSV (NA) or glycosylation at position 46 of GP5 in a European PRRSV (EU); and use of a second GP5-M heterodimer, where GP5 of the second GP5-M heterodimer has no glycosylation at position 44 of GP5 in a North American PRRSV (NA) or position 46 of GP5 in a European PRRSV (EU) ), to generate antibodies against a protective antigenic determinant (PAD) of PRRSV.

28. An isolated antibody, characterized in that it is produced by a method comprising: administering to an animal a first GP5-M heterodimer, wherein the GP5 of the first GP5-M heterodimer has glycosylation at position 44 of GP5 in a North American PRRSV (NA) or glycosylation at position 46 of GP5 in a European PRRSV (EU); and administering to the animal a second GP5-M heterodimer, wherein the GP5 of the second GP5-M heterodimer has no glycosylation in the position 44 of GP5 in a North American PRRSV (NA) or in position 46 of GP5 in a European PRRSV (EU), thus generating antibodies against a protective antigenic determinant (PAD) of PRRSV.

29. A method for preparing a vaccine for generating antibodies against PAD of PRRSV, characterized in that it comprises: providing a sequence comprising a heterodimer of a protein of matrix (protein M) of the virus of porcine reproductive and respiratory syndrome (PRRSV) and a glycoprotein 5 (GP5) of PRRSV, wherein the GP5 protein has N-glycosylation of amino acids asparagine located at position 44 of the GP5 protein in North American PRRSV strains or at position 46 of the GP5 protein in European PRRSV strains.

30. The method of compliance with the claim 29, characterized in that it further comprises: mixing the polypeptide with a physiologically acceptable carrier.

31. A method for preparing a vaccine to generate antibodies against PAD of PRRSV, characterized in that it comprises: providing a sequence comprising a heterodimer of a protein matrix (protein M) of porcine reproductive and respiratory syndrome virus (PRRSV) and a glycoprotein 5 (GP5) of PRRSV, where the GP5 protein has no N-glycosylation of amino acids asparagine located at position 44 of the GP5 protein in strains of PRRSV North American or in position 46 of the GP5 protein in European PRRSV strains.

32. The method according to claim 31, characterized in that it further comprises: mixing the polypeptide with a physiologically acceptable carrier.

33. A vaccine for protection against PRRSV infection, characterized in that it comprises a polypeptide, wherein the polypeptide comprises the polypeptides according to claim 23 and 25 in an amount effective to protect against PRRSV infection.

34. The vaccine according to claim 33, characterized in that the polypeptides are administered sequentially or concurrently.

35. A method for vaccinating pigs, characterized in that it comprises: administering to a pig the vaccine according to claim 32 in an amount effective to protect against PRRSV infection when administered to a susceptible host.

36. Use of a first GP5-M heterodimer, where the GP5 of the first GP5-M heterodimer has glycosylation at position 44 of GP5 in a North American PRRSV (NA) or glycosylation at position 46 of GP5 in a European PRRSV (EU); and use of a second GP5-M heterodimer, wherein the GP5 of the second GP5-M heterodimer has no glycosylation in the position 44 of GP5 in a North American PRRSV (NA) or in position 46 of GP5 in a European PRRSV (EU), for the manufacture of a vaccine to treat a PRRSV infection in a pig.

37. A method for treating PRRSV infections in a pig, characterized in that it comprises: administering the antibody according to claim 28 to an animal that requires treatment.

38. A method to detect antibodies against a protective antigenic determinant (PAD) of PRRSV in an animal, characterized in that it comprises: incubating a biological sample from an animal with the polypeptide according to claim 23 or 25 for a time sufficient for the binding of the antibody to take place and determining the binding of the antibody to the polypeptide.

39. A multivalent vaccine, characterized in that it comprises GP5-M protein heterodimers of PRRSV and a polypeptide comprising: a sequence comprising a heterodimer of a porcine reproductive and respiratory syndrome virus protein (M protein) protein (PRRSV) and a PRRSV glycoprotein 5 (GP5), wherein the GP5 protein has N-glycosylation of amino acids asparagine located at position 44 of the GP5 protein in North American PRRSV strains or at position 46 of the GP5 protein in European PRRSV strains and a sequence comprising a heterodimer of a porcine reproductive and respiratory syndrome virus protein (M protein) protein (PRRSV) and a PRRSV glycoprotein 5 (GP5), where the GP5 protein has no N-glycosylation of amino acids asparagine located at position 44 of the GP5 protein in North American PRRSV strains or in position 46 of the GP5 protein in European PRRSV strains.

40. A subunit vaccine of the GP5-M heterodimer, characterized in that it comprises: a polypeptide comprising a sequence containing a heterodimer of a matrix protein (protein M) of the porcine reproductive and respiratory syndrome virus (PRRSV) and a glycoprotein 5 (GP5) of PRRSV, wherein the GP5 protein has N-glycosylation of amino acids asparagine located at position 44 of the GP5 protein in North American PRRSV strains or at position 46 of the GP5 protein in European PRRSV strains, and a polypeptide comprising a sequence comprising a heterodimer of a porcine reproductive and respiratory syndrome virus protein (M protein) heterodimer (PRRSV) and a PRRSV glycoprotein 5 (GP5), wherein the GP5 protein has no amino acid N-glycosylation asparagine at position 44 of the GP5 protein in North American PRRSV strains or position 46 of the GP5 protein in European PRRSV strains.

41. The subunit vaccine in accordance with claim 40, characterized in that it further comprises a PRRSV M protein heterodimer and PRRSV GP5, wherein the GP5 protein is linked to the M protein by a disulfide bond, wherein the disulfide bond results from binding between a amino acid cysteine in the M protein located in the 9 position in the North American PRRSV strains or in the 8 position in the strains of EU PRRSV with an amino acid cysteine in the 48 position of the GP5 protein in North American PRRSV strains or in the 50 position in European PRRSV strains, thus producing a GP5-M heterodimer.

42. The subunit vaccine according to claim 41, characterized in that the GP5 further comprises at least one glycosylated amino acid of amino acids 1-43 of the GP5 ectodomain in North American PRRSV strains or amino acids 1-45 of the ectodomain of GP5 in European PRRSV strains.

43. An isolated polypeptide useful for generating a protective effect against PRRS, characterized in that it comprises: a sequence containing a heterodimer of a porcine reproductive and respiratory syndrome virus protein (M protein) (PRRSV) and a glycoprotein 5 (GP5) ) of PRRSV, wherein the GP5 protein is linked to the M protein by a disulfide bond, where the disulfide bond results from the binding between a amino acid cysteine in the M protein located in position 9 in North American PRRSV strains or in position 8 in strains of EU PRRSV with an amino acid cysteine at position 48 of the GP5 protein in North American strains of PRRSV or in position 50 of strains of European PRRSV, thus producing a GP5-M heterodimer.

44. A method for preparing a vaccine for generating a protective response to PRRSV exposure, characterized in that it comprises determining the number of glycans of glycoprotein 5 (GP5) of a PRRSV strain, and preparing a vaccine comprising a GP5 having less glucans than the PRRSV strain.

45. A method for preparing a vaccine for generating a protective response to PRRSV exposure, characterized in that it comprises preparing a vaccine containing a PRRSV glycoprotein 5 (GP5), wherein the glycosylation of GP5 is selected from the group consisting of glucan, glucans present in position 44 in North American PRRSV strains, glucans present in position 51 of North American PRRSV strains, glucans present in positions 44 and 51 of North American PRRSV strains, glucans present in position 46 in strains of PRRSV European, glucans present in position 53 in European PRRSV strains and glucans present in positions 46 and 53 of the GP5 protein in European PRRSV strains.

46. A method for grouping strains of PRRSV, characterized in that it comprises determining the number of glucans and the position of the glucans in a glycoprotein 5 (GP5) of PRRSV, and grouping the strain with strains having the same number of glucans in the same position. 47. A method for generating antibodies against PRRSV, characterized in that it comprises: administering to a subject a sequence comprising a heterodimer of a protein of the porcine reproductive and respiratory syndrome virus (M protein) protein

(PRRSV) and a PRRSV glycoprotein 5 (GP5), wherein the GP5 protein is linked to the M protein by a disulfide bond, where the disulfide bond results from the binding between an amino acid cysteine in the M protein located in position 9 in North American PRRSV strains or in position 8 in strains of EU PRRSV with an amino acid cysteine at position 48 of the GP5 protein in North American PRRSV strains or in position 50 of European PRRSV strains, thus generating antibodies against PRRSV. 48. A method to generate antibodies against

PRRSV, characterized in that it comprises determining the number of glycans of glycoprotein 5 (GP5) of a PRRSV strain, administering to a subject a PRRSV comprising a GP5 that has fewer glucans than the PRRSV strain, thus generating antibodies against PRRSV .

49. A method for generating antibodies against PRRSV, characterized in that it comprises preparing a vaccine containing a PRRSV glycoprotein 5 (GP5), wherein the glycosylation of GP5 is selected from the group consisting of no glucan, glucans present at position 44 in strains of American PRRSV, glucans present in position 51 in North American PRRSV strains, glucans present in positions 44 and 51 in North American PRRSV strains, glucans present in position 46 in European PRRSV strains, glucans present in position 53 in strains of European PRRSV and glucans present in positions 46 and 53 of the GP5 protein in European PRRSV strains, and administer the prepared vaccine to a subject, thus generating antibodies against PRRSV.

50. A method for vaccinating against PRRSV, characterized in that it comprises: administering to a subject a sequence comprising a heterodimer of a protein of matrix (protein M) of the virus of the reproductive and respiratory respiratory syndrome (PRRSV) and a glycoprotein 5 (GP5) of PRRSV, wherein the GP5 protein is linked to the M protein by a disulfide bond, wherein the disulfide bond results from the binding between an amino acid cysteine in the M protein located at position 9 in the North American PRRSV strains or in position in the strains EU PRRSV with a cysteine amino acid in position 48 of the GP5 protein in North American PRRSV strains or in position 50 of European PRRSV strains, thus vaccinating against PRRSV.

51. A method for vaccinating a subject against PRRSV, characterized in that it comprises: determining the number of glycans of glycoprotein 5 (GP5) of a PRRSV strain, preparing a vaccine comprising a GP5 having fewer glycans than the PRRSV strain , and administer the vaccine to the subject.

52. A method for vaccinating a subject against PRRSV, characterized in that it comprises: preparing a vaccine comprising a glycoprotein 5 (GP5) of PRRSV, wherein the glycosylation of GP5 is selected from the group consisting of no glucan, glucans present in the position 44 in North American PRRSV strains, glucans present in position 51 of North American PRRSV strains, glucans present in positions 44 and 51 of North American PRRSV strains, glucans present in position 46 of European PRRSV strains, glucans present in the position 53 in European PRRSV strains and glucans present in positions 46 and 53 of the GP5 protein in European PRRSV strains, and administer the vaccine to the subject.

53. A vaccine, characterized in that it comprises: a sequence containing a heterodimer of a protein of matrix (protein M) of the virus of the porcine reproductive and respiratory syndrome (PRRSV) and a glycoprotein 5 (GP5) of PRRSV, wherein the GP5 protein is linked to the M protein by a disulfide bond, where the disulfide bond results from the binding between a cysteine amino acid in the M protein located at position 9 in North American PRRSV strains or in position 8 in EU PRRSV strains with a cysteine amino acid at position 48 of the GP5 protein in North American PRRSV strains or in position 50 of European PRRSV strains.

54. A PRRSV vaccine, characterized in that it is prepared by a method comprising determining the number of glycans of glycoprotein 5 (GP5) of a PRRSV strain, and preparing a vaccine comprising a GP5 having fewer glucans than the PRRSV.

55. A PRRSV vaccine, characterized in that it comprises a PRRSV glycoprotein 5 (GP5), wherein the glycosylation of GP5 is selected from the group consisting of no glucan, glucans present at position 44 in North American PRRSV strains, glucans present in position 51 of North American PRRSV strains, glucans present in positions 44 and 51 of North American PRRSV strains, glucans present in position 46 in European PRRSV strains, glucans present in position 53 in European PRRSV strains and glucans present in positions 46 and 53 of the GP5 protein in European PRRSV strains.