RU2214277C1 - Virus vaccine against infectious laryngotracheitis in poultry - Google Patents

Abstract

FIELD: veterinary virology, biotechnology. SUBSTANCE: the suggested virus vaccine contains virus-containing material out of attenuated "O" strain of poultry infectious laryngotracheitis virus and protective medium in efficient ratios. The strain in question is deposited in collection of microorganisms of VGNKI at registration name of "O N112- DEP". Virus should be reproduced in 9-11-d-aged embryos of SPF-hens at biological activity of not less than 6,0lg EID_50/cu.cm. To obtain protective medium one should apply (either separately or in combination) saccharose, gelatose, lactose, etc. Virus vaccine is of high immunogenic activity; it is safe and reveals areactogenicity in case of ocular and oral ways of immunization. EFFECT: higher efficiency. 4 cl, 8 ex, 7 tbl

Description

 The invention relates to the field of veterinary virology and biotechnology and can be used in the development and production of means of specific prophylaxis of infectious laryngotracheitis (ILT) of birds.

 ILT, an acute contagious disease of birds, is the cause of a high mortality rate (usual mortality is 10-20%, there are cases of high mortality, which is 50-70%), in cases of ill individuals the daily gain and egg production are reduced. ILT is caused by herpes virus. One of the main means of combating ILT is vaccination with live and inactivated vaccines.

 The advantages of virus vaccines are that they are suitable for mass use by watering, aerosol spraying, etc., a relatively small amount of an immunizing drug is required for immunization of birds, since live antigen continues to multiply in the body of an immunized bird, they are cheaper to manufacture and their storage requires relatively little space in refrigeration units.

 Known virus vaccine against bird ILT, containing virus-containing material from an attenuated strain "G" of a homologous virus reproduced in a sensitive biological system, and a protective environment in an effective ratio [1].

 Known virus vaccine against ILT in birds, containing virus-containing material from an attenuated strain "TsNIIPP" homologous virus reproduced in a sensitive biological system and a protective environment in an effective ratio [2].

 Known virus vaccine against bird ILT, containing virus-containing material from the clone "NT" attenuated strain "TsNIIPP" homologous virus reproduced in a sensitive biological system, and a protective environment in an effective ratio [3].

 The disadvantages of known virus vaccines are their low immunogenic activity. These vaccines form an immunity that cannot protect 100% of the poultry head from being infected with the epizootic ILT virus.

 The closest to the invention according to the set of essential features is a bird vaccine against ILT, containing virus-containing material from the attenuated strain "VNIIBP" homologous virus reproduced in a sensitive biological system, and a protective environment in an effective ratio [4].

 The disadvantage of the prototype virus vaccine is its low immunogenic activity and increased reactogenicity.

 In this regard, the urgent problem remains the creation of a virus vaccine, which has both high immunogenic activity, harmlessness and areactogenicity with ocular and oral methods of immunization.

 The objective of the present invention was to expand the arsenal of highly immunogenic and harmless virus vaccines against bird ILT.

 The technical result from the use of the invention is to expand the arsenal of virus vaccines against ILT in birds with high immunogenic activity, harmlessness and areactogenicity in ocular and oral methods of immunization.

The specified technical result was achieved by the creation of a virus vaccine against bird ILT, characterized by the following set of features:
1. Virus vaccine against ILT birds.

 2. Virus-containing material from attenuated strain "O" of bird ILT virus.

3. Virus-containing material from attenuated strain “O” of bird ILT virus reproduced in 9-11-day-old embryos of SPF chickens with biological activity of at least 6.0 Ig EID _{50 / cm} ³ .

4. Virus-containing material from attenuated strain "O" of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity of not less than 6.0 Ig EID _{50 / cm} ³ in an effective amount.

5. Virus-containing material from the attenuated strain "O" reproduced in 9-11-day-old embryos of SPF-chickens with biological activity of not less than 5.2 Ig EID _{50 / cm} ³ in an amount of 85.0-95.0 wt.%.

 6. A protective medium containing (alone or in combination) lactose, gelatose, sucrose, etc., in an amount of 5.0-15.0 wt.%.

7. Virus-containing material from attenuated strain “O” of bird ILT virus reproduced in 9-11-day-old embryos of SPF chickens with biological activity of at least 6.0 Ig EID _{50 / cm} ³ and the protective medium are taken in the ratio, wt.% :
Virus-containing material - 85.0-95.0
Protective environment - Up to 100.0
The present invention includes the following set of essential features that provide a technical result in all cases for which legal protection is sought:
1. Virus vaccine against ILT birds.

 2. Virus-containing material from attenuated strain "O" of bird ILT virus reproduced in a sensitive biological system.

 3. Virus-containing material from an attenuated strain “O” of bird ILT virus reproduced in a sensitive biological system in an effective amount.

 4. Protective environment.

 5. Virus-containing material from the attenuated strain "O" of bird ILT virus reproduced in a sensitive biological system, and a protective environment in an effective ratio.

The present invention is also characterized by other features expressing specific forms of execution or special conditions for its use:
1. Virus-containing material from attenuated strain “O” of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity of not less than 6.0 Ig EID _{50 / cm} ³ .

2. Virus-containing material from attenuated strain “O” of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity not less than 6.0 Ig EID _{50 / cm} ³ , in the amount of 85.0-95.0 wt. .%.

 3. The protective environment in the amount of 5.0-15.0 wt.%.

4. Virus-containing material from attenuated strain “O” of bird ILT virus reproduced in 9-11-day-old embryos of SPF chickens with biological activity of not less than 6.0 Ig EID _{50 / cm} ³ and the protective medium is taken in the ratio, wt.% :
Virus-containing material - 85.0-95.0
Protective environment - Up to 100.0
The signs of the invention, characterizing the proposed vaccine and coinciding with the signs of the prototype, including the generic concept, reflecting the purpose, are:
1. Virus vaccine against ILT birds.

 2. Virus-containing material from an attenuated strain of avian ILT virus reproduced in a sensitive biological system.

 3. Protective environment.

Compared with the prototype virus vaccine, the salient features of the invention are:
1. Of the attenuated strains of the virus vaccine contains the attenuated strain "O" of the bird ILT virus.

 2. Strain "O" virus ILT birds in an effective amount.

The present invention is also characterized by other distinctive features that express specific forms of execution or special conditions for its use:
1. Virus-containing material from attenuated strain “O” of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity of not less than 6.0 Ig EID _{50 / cm} ³ .

2. Virus-containing material from attenuated strain “O” of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity not less than 6.0 Ig EID _{50 / cm} ³ , in the amount of 85.0-95.0 wt. .%.

 3. The protective environment in the amount of 5.0-15.0 wt.%.

4. Virus-containing material from attenuated strain “O” of bird ILT virus reproduced in 9-11-day-old embryos of SPF chickens with biological activity of not less than 6.0 Ig EID _{50 / cm} ³ and the protective medium is taken in the ratio, wt.% :
Virus-containing material - 85.0-95.0
Protective environment - Up to 100.0
The proposed virus vaccine has a high immunogenic activity, harmlessness and areactogenicity with ocular and oral methods of immunization.

 The achievement of the technical result from the use of the proposed virus vaccine is due to the fact that it contains antigenic material from the attenuated strain "O" of the ILT virus, which has high biological, antigenic and immunogenic activity in its native form and after inactivation.

 The initial virus for obtaining strain "O" was isolated from the larynx and trachea of chicken with signs of a latent form of the disease in Kazakhstan in 1992.

 Production strain "O" was obtained by repeated consecutive passages on 9-11-day-old embryos of SPF hens.

 Strain "O" was deposited in the All-Russian State Collection of strains of microorganisms used in veterinary medicine and animal husbandry, the All-Russian State Research Institute of Control, Standardization and Certification of Veterinary Medicines (VGNKI) 05.06.2000 under the registration name "O 112-DEPT".

 Strain "O" has a high biological, antigenic and immunogenic activity in its native form and after inactivation.

 The possibility of its use for the manufacture of a virus vaccine with high immunogenic activity and harmlessness in ocular and oral immunization methods has been experimentally confirmed.

 Strain "O" virus ILT birds is characterized by the following features and properties.

Morphological properties
Strain "O" of the ILT virus belongs to the Herpesviridae family. Electron microscopy (instrumental magnification of 4.5 • 10 ⁵ and 5 • 10 ⁵ ) in the field of view of the microscope shows clearly distinguishable viral particles of ILT with their characteristic morphology. Virions have a spherical shape, their sizes vary from 200 to 250 nm (in some up to 330 nm). ILT virions are composed of a spherical nucleotide surrounded by a complex-shaped supercapsid membrane. Virion has an icosahedral type of symmetry. The icosahedral capsid is covered with a lipoprotein membrane, which has peplomer units on its surface. The nucleocapsid dimer is 113 + 2 nm, the average diameter of the shell nucleocapsid is about 350 nm.

 Nucleocapsids 100-110 nm in size are located in the viral particle, usually eccentric, less often in the center of the particles. The genome of the ILT virus has a length of 155,000 polynucleotides and consists of a long unique sequence of I1 (120,000 polynucleotides) and a short unique sequence of Is (17,000 polynucleotides). The virus contains glycoproteins (205, 160, 115, 90, 85, 74, 60 and 50 kD). Glycoprotein B (gB) is the first structural protein of the ILT virus.

Antigenic properties
Strain "O" of the ILT virus is stably neutralized by homologous serum, is identified in the blood serum of chickens containing antibodies to this virus, in RDP, PH and ELISA. In RDP, it is identified by homologous hyperimmune sera in a titer of 1: 8. In pH, the neutralization index of homologous hyperimmune sera at dilutions of 1:10 and 1:20 averages 3.8 Ig EID ₅₀ / cm ^3, respectively. In ELISA is identified by field and laboratory hyperimmune sera in the titer up to 1: 24579. Antigenic differences of strain "O" in relation to other strains of the ILT virus have not been established. The strain does not have hemagglutinating properties.

Biotechnological characteristics
Strain "O" exhibits high biological, immunogenic and antigenic activity both in its native form and after inactivation. Strain "O" is used for the manufacture of live and inactivated vaccines against bird ILT and diagnostic preparations. The virus has a pronounced tropism to the epithelial cells of the mucous membrane of the larynx, trachea and cloaca of birds. The strain is cultured in 9-11 day old SPF chicken embryos. Reproduction of the virus occurs in the tissue of the chorio-allantoic membrane (HAO). The infectious titer of the virus in a 10-20% suspension of HAO on the 5th day of cultivation under the condition of generalized distribution throughout the membrane is at least 6.0 Ig EID ₅₀ / cm ³ .

Chemo- and genotaxonomic characterization
Strain "O" is a DNA-containing virus.

Resistance to external factors
The virus is sensitive to lipolytic agents, heat and various disinfectants. A temperature of 55 ^o C destroys the virus within 10-15 minutes, and 38 ^o C - in 48 hours. The virus remained active for more than 19 months in the frozen carcasses of sick and involuntarily killed chickens stored at a temperature of minus 10, 18 and 28 ^o С, 12 hours were inactivated on the surface of the shell in a thermostat, and no more than 9 days remained in infected houses. Fully inactivated in a 1% solution of creolin for 30 seconds. It retains its activity for a long time in a lyophilized state or at minus 20-60 ^o C. In the lyophilized homogenate of HAO, the virus retains an infectivity of at least 1.5. In a frozen HAO tissue, the virus remains infectious for at least 4 years.

The immunogenicity of the strain
When vaccinating chickens older than 15 days of age, the ocular method at a dose of 1000 EID50 and the oral method (drink) at a dose of 4000 EID ₅₀ induces the production of specific antibodies and creates immunity against ILT in 100% of vaccinated chickens. In the lyophilized HAO homogenate, the virus retains immunogenicity for at least 1.5 years.

Epizooticity of the strain
When vaccinated and intact birds were kept together, transmission of the vaccine virus of strain “O” by contact was not established.

The condition for maintaining the strain
Lyophilized material from strain "O" is stored at a temperature of 4 ^o C, virus-containing HAO - at a temperature not exceeding minus 40 ^o C. To resuspend the lyophilized virus using isotonic phosphate-buffered solution pH 7.4-7.6.

Genetic purity
After 20 passages on the Khao 9-11-day-old embryo of SPF-hens, no changes in the immunobiological properties of strain "O" were found.

Additional features and properties
Reactogenicity is absent.

 Pathogenicity is absent.

 Virulence is absent.

 Oncogenicity is absent.

 There is no contagiousness.

 The attenuation stability was observed during 4 passages on sensitive chickens.

 Based on the data obtained, it can be argued that the strain "O" of the ILT virus according to antigenic and immunological spectra is an original, taxonomically new, previously unknown variant of the ILT virus.

 The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information and identification of sources containing information about analogues of the invention, allowed to establish that the applicant did not find sources characterized by features that are identical (identical) to all the essential features of the invention. The definition from the list of identified analogues of the prototype as the closest in terms of the totality of the features of the analogue made it possible to establish a set of essential distinguishing features of the proposed virus vaccine relative to the applicant's technical result, as set forth in the independent claim.

 Therefore, the claimed solution meets the condition of patentability "novelty."

 To verify the conformity of the proposed solution to the patentability condition "inventive step", an additional search was carried out for known solutions to identify features included in the distinctive part of the independent claim. The search results showed that the proposed solution does not follow explicitly for the specialist from the prior art set forth in the corresponding section of the description (no solutions having features matching the distinguishing features of the present invention have been identified), and the effect of the transformations provided for by the essential features of the proposed invention has not been identified to achieve a technical result.

 Therefore, the proposed virus vaccine meets the condition of patentability "inventive step".

 The essence of the invention is illustrated by examples of its execution, which do not limit the scope of the invention.

 Example 1

For the manufacture of virus vaccines, avirulent for chickens and harmless to humans production strain “O” of bird ILT virus with biological activity of not less than 6.0 Ig EID ₅₀ / cm ³ , which is stored in a lyophilized state, is used. For reproduction of the virus using 9-11-day-old embryos of SPF-chickens. Eggs for chicken embryos are obtained from farms that are safe for infectious diseases, including ILT, or from SPF laying hens unvaccinated against ILT. In order to obtain mother seed brood, the contents of three ampoules of the production strain “O” are diluted 1: 5 with a sterile physiological solution of pH 7.2–7.4 with the addition of antibiotics and the resulting virus infects well-developed 9–11-day-old embryos in the allantoic cavity in a volume of 0 , 2 cm ³ . Infected embryos are incubated at a temperature of 37.0 ± 0.5 ^o C and a relative humidity of 60-70% for 5 days.

On the 6th day, the characteristic lesions of HAO are determined for the ILT virus. A 15-30% suspension is prepared from the affected HAO, which is frozen and freed from coarse particles by low-speed centrifugation. The resulting virus-containing material with a biological activity of not less than 6.0 Ig EID50 / cm ^{3 is} used as a matro brood for mass infection of 9-11-day-old SPF-chicken embryos. Embryos are infected with a mother virus in a volume of 0.2 cm ³ . Infected embryos are kept in a thermostat at 37.5 ± 0.5 ^o C and a relative humidity of 60-70% for 5 days. All embryos and survivors who died after 72 hours of incubation are placed in refrigerated chambers at 2-6 ^o C for 16-18 hours. After cooling, the infected embryos are opened, HAO is removed with characteristic changes (specific nodule plaques). Affected HAO is placed in a refrigerator at a temperature not exceeding minus 40 ^o C. HAO is used to prepare virus-containing material. For this, the affected HAOs are thawed and a homogeneous homogeneous mass is prepared from them. The resulting virus-containing material is mixed with a protective medium in a ratio of 17: 3-19: 1, which is necessary to obtain a vaccine with a given immunogenic activity. The ingredients of the protective environment are substances widely used for these purposes (separately or in combination): sucrose, gelatose, lactose, skim milk, etc. A mixture of virus-containing material and a protective environment is thoroughly mixed. The resulting mixture is monitored for sterility, hemagglutinating activity (HA activity) in a drop of RGA and for determining the titer of the virus before lyophilization. The biological activity of the semi-finished vaccine, which is going to prepare the vaccine, when titrated at the RCE should not be lower than 6.0 Ig EID ₅₀ / cm ³ . After obtaining positive control results, the semi-finished vaccine is cooled to 2-8 ^° C and packaged in sterile ampoules or penicillin vials so that the layer thickness of the spilled liquid semi-finished product is not more than 1/2 the height of the ampoule or vial. Ampoules and semi-finished vials are placed in special metal cassettes, which are then installed in a refrigerator with a temperature of (60 ± 5 ^° C) for 8-24 hours, depending on the volume of the suspension in ampoules and vials. The frozen semi-finished product is subjected to lyophilization. The drying time for the semi-finished product is 56-72 hours, depending on the design of the sublimation unit and the level of material in the vial or ampoule. At the end of drying, the bottles with the dry vaccine are corked and sealed with aluminum caps. Ampoules with dry vaccine are sealed. The dry virus vaccine against ILT of birds from strain "O" is a homogeneous porous in the form of a tablet or an amorphous mass of light brown color. Mass fraction of moisture - not more than 3%. The biological activity of the virus in the vaccine should be at least 5.2 Ig EID ₅₀ / cm ³ .

 The resulting avian vaccine against ILT birds has the optimal component composition (formulation), are shown in table 1.

 The content of virus-containing material in the range of 85.0-95.0 wt. % represents the effective amount of antigen in the proposed vaccine.

 Before use, the virus vaccine is diluted with a diluent, which is a 5% solution of glycerol in a phosphate-buffered solution, labeled with a neutral food coloring such as indigo carmine, and is intended for the preparation of a working dilution of the vaccine with the ocular method of immunizing birds and bringing the pH of water close to neutral or slightly alkaline, when using the vaccine by evaporation.

 The proposed virus vaccine immunizes clinically healthy birds older than 15 days of age. Birds up to 60 days of age are vaccinated twice with an interval of 14 days. Immunity is formed 21 days after vaccination. Revaccination is carried out every 6 months.

 Example 2

Tests of the virus vaccine against ILT of birds, made as described in example 1, and containing, wt.%:
Virus-containing material from attenuated strain "O" of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity not less than 6.0 Ig EID ₅₀ / cm ³ - 85.0;
The protective environment is up to 100.0.

The immunogenic activity of the vaccines was determined in chickens. For this, dilution of vaccines on a diluent was preliminarily prepared: for the ocular immunization method, so that 0.05 cm ³ (the volume of one drop) contained 1000 EID ₅₀ , for the oral one, that 4000 EID _{50 were} contained in 1 cm ³ . In the experiment, 50 chickens were taken and 20 of them were immunized ocularly (1 drop per eye), 20 orally (they were fed 1 cm ³ ), and 10 chickens were left for control. Eighteen days after vaccination, the experimental and control chickens were infected with the virulent Bogatischevsky strain of avian ILT virus. The virus was administered intratracheally at a dose of 500 EID ₅₀ in a volume of 0.5 cm ³ . Chickens were observed for 10 days. A vaccine is considered immunogenic if it protects 16 chickens out of 20 vaccinated against ILT disease. In the control group, at least 8 chickens out of 10 infected should be ill with signs of ILT. The test results are shown in table 2, which indicate that all three series of virus vaccines against ILT birds from strain "O", made according to the above recipe, in all respects meet the requirements laid down in the technical specifications for the drug, and are almost equally effective in ocular and oral administration in poultry. In the control groups of chickens, the incidence of ILT was 100%, while the mortality rate was 48.6%.

 Example 3

Tests of the immunogenic activity of the viral vaccine against bird ILT, made as described in example 1, and containing, wt.%:
Virus-containing material from attenuated strain "O" of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity of not less than 6.0 Ig EID ₅₀ / cm ³ - 90.0;
The protective environment is up to 100.0.

 This formulation of the proposed virus vaccine was tested as described in example 2. The experiments were carried out three times. The test results are shown in table 3, which indicate that all three series of virus vaccines made according to the above recipe against ILT birds from strain "O", in all respects meets the requirements laid down in the technical specifications for the drug, and are almost equally effective in ocular and oral administration to poultry. In the chickens of the control groups, the incidence of ILT was 100%, the mortality rate in 3 experiments was 45.8%.

 Example 4

Tests of the immunogenic activity of the viral vaccine against bird ILT, made as described in example 1, and containing, wt.%:
Virus-containing material from attenuated strain "O" of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity not less than 6.0 Ig EID _{50 / cm} ³ - 95.0;
The protective environment is up to 100.0.

 This formulation of the proposed virus vaccine was tested as described in example 2. The experiments were carried out three times. The test results are shown in table 4, which indicate that all three series of virus vaccines against ILT birds from strain "O", made according to the above recipe, in all respects meet the requirements laid down in the technical conditions for the drug and are almost equally effective in ocular and oral administration in poultry. In the control groups of chickens, the incidence of ILT was 100%, while the mortality rate in 3 experiments was 50.2%.

 Example 5

Comparative tests of the immunogenic activity of a virus vaccine against ILT birds, made as described in example 1, and containing, wt.%:
Virus-containing material from attenuated strain "O" of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity of 6.0 Ig EID ₅₀ / cm ³ - 85.0;
Protective environment - up to 100.0,
and virus vaccines against ILT of birds made on the basis of well-known domestic and foreign strains of a homologous virus: the Laryngo-vac virus vaccine (Holland), the virus vaccine from the NT clone of the TsNIIPP strain and the virus vaccine from the VNIIBP strain (prototype). The study of the immunogenic activity of these vaccines was carried out on SPF chickens of 25 days of age. All chickens were orally and ocularly administered a single dose of the above vaccines. Evaluation of the effectiveness of the vaccines was carried out according to the results of the control of infection with the virulent strain "Bogatishchevsky" virus ILT. The results of the studies are presented in table 5.

 The data in table 5 indicate that during the control infection of vaccinated chickens with the virulent strain "Bogatishchevsky" of the ILT virus, only the virus vaccine from strain "O" of this formulation induced immunity to ILT in 100% of the vaccinated chickens.

 Example 6

Comparative tests of the immunogenic activity of a virus vaccine against ILT birds, made as described in example 1, and containing, wt.%:
Virus-containing material from attenuated strain "O" of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity of not less than 6.0 Ig EID _{50 / cm} ³ - 90.0;
Protective environment - up to 100.0,
and virus vaccines against ILT of birds made on the basis of well-known domestic and foreign strains of a homologous virus: the Laryngo-vac virus vaccine (Holland), the virus vaccine from the NT clone of the TsNIIPP strain and the virus vaccine from the VNIIBP strain (prototype). The studies were carried out as described in example 5. The research results are presented in table 6.

 The data in table 6 indicate that during the control infection of vaccinated chickens with the virulent strain "Bogatishchevsky" of the ILT virus, only the virus vaccine from strain "O" of this formulation induced immunity to ILT in 100% of the vaccinated chickens.

 Example 7

Comparative tests of the immunogenic activity of a virus vaccine against ILT birds, made as described in example 1, and containing, wt.%:
Virus-containing material from attenuated strain “O” of bird ILT virus reproduced in 9-11-day-old embryos of SPF chickens with biological activity of 6.2 Ig EID ₅₀ / cm ³ - 95.0;
Protective environment - up to 100.0,
and virus vaccines against ILT of birds made on the basis of well-known domestic strains of a homologous virus: Laryngo-vac virus vaccine (Holland), virus vaccine from the NT clone of the TsNIIPP strain and virus vaccine from the VNIIBP strain (prototype). The studies were carried out as described in example 5. The research results are presented in table 7.

 The data in table 7 indicate that during the control infection of vaccinated chickens with the virulent strain "Bogatishchevsky" of the ILT virus, only the virus vaccine from strain "O" of this formulation induced immunity to the ILT of 100% of vaccinated chickens.

 Example 8

Tests of the immunogenic activity of the viral vaccine against bird ILT, made as described in example 1, and containing, wt.%:
Virus-containing material from attenuated strain "O" of bird ILT virus reproduced in 9-11-day-old embryos of SPF-chickens with biological activity of not less than 6.0 Ig EID _{50 / cm} ³ - 90.0;
The protective environment is up to 100.0.

 The tests were carried out in the unsuitable for bird ILT GUP-APK "Nazarievo" of the Odintsovo district of the Moscow region. Virus vaccine against ILT of birds from strain O was immunized with 240 thousand poultry, of which 80 thousand broilers and 160 thousand laying hens and repair young calves Heidex white breed. Vaccination was carried out by the method of drinking according to the instruction on the use of the drug. Observation of the vaccinated livestock revealed that in a dysfunctional house the sick bird continued for another 6 days, after which the clinical signs of the disease disappeared and the physiological state of the chickens returned to normal. In poultry houses, where there were no signs of ILT, no adverse reactions to vaccination were seen.

 The well-being of the ILT in the economy is preserved to this day.

Thus, the above information indicates the fulfillment when using the invention of the following set of conditions:
- virus vaccine against bird ILT, embodying the invention, is intended for use in agriculture, namely in veterinary virology and biotechnology;
- for the proposed invention in the form described in the independent claim, the possibility of its implementation using the means and methods described in the application or known prior to the priority date has been confirmed;
- when using the proposed virus vaccines against ILT birds based on strain "O" the technical result is achieved, provided for by the task of creating the invention.

 Therefore, the present invention meets the condition of patentability "industrial applicability".

Sources of information
1. Babkin V.F. and other Veterinary medicine. Rep. Mizh. view. thematic sciences. zb. Kiev, 1975, no. 42, 14-19.

 2. Auth. testimonial. USSR 129791; 30 h, 6; 1960 year

 3. Dutko Yu.S., Shevchenko A.A. and others. Immunological efficacy of a vaccine against infectious laryngotracheitis of hens. Veterinary Medicine, 1991, 3, 32-34.

 4. Malushko V.V., Sokolov V.D. et al. Experience in combating infectious laryngotracheitis. Poultry farming, 1982, 12, 21-23 (prototype).

Claims (5)

 1. Virus vaccine against infectious laryngotracheitis of birds, containing virus-containing material from an attenuated strain of a homologous virus reproduced in a sensitive biological system, and a protective medium, characterized in that of the attenuated strains it contains a strain of the virus of infectious laryngotracheitis of birds, VGNKI collection "O 112-DEP" , in an effective amount. 2. The virus vaccine according to claim 1, characterized in that it contains virus-containing material from the attenuated strain "O 112-DEPT" of the pathogen, reproduced in 9-11-day-old embryos of SPF-chickens with biological activity of not less than 6.0 Ig EID ₅₀ / cm ³ .  3. Virus vaccine according to claim 2, characterized in that it contains a virus-containing material from an attenuated strain "O 112-DEPT" of the pathogen of infection in an amount of 85.0-95.0 wt.%.  4. The virus vaccine according to claim 1, characterized in that it contains a protective environment in an amount of 5.0-15.0 wt.%. 5. Virus vaccine according to any one of claims 1 to 4, characterized in that it contains virus-containing material from strain "O 112-DEPT" of the pathogen and the protective medium in a ratio, wt.%:
Virus-containing material - 85.0-95.0
Protective environment - Up to 100.0 h

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