RU2128223C1 - Strain a/17/nanchang/95/4 (h3n2) for production of living an antiinfluenza intranasal vaccine for adults - Google Patents

Abstract

FIELD: medicine, virology, vaccines. SUBSTANCE: invention relates to preparing living an antiinfluenza living vaccine for adults and children corresponding to an actual virus A/Nanchang/933/ 95 (H3N2) by antigenic properties. Vaccine strain A/17/ Nanchang/95/4 (H3N2) is a reassortant obtained by breeding an epidemic virus A/Nanchang/933/95 (H3N2) with cold-adapted temperature-sensitive virus A/Leningrad/134/17/57 (H2N2) as an attenuation donor. Strain is harmless for adults, its properties provide preparing reassortant vaccine strains from newly appearing epidemic viruses. Strain A/17/Nanchang/95/4 (H3N2) multiplicates actively in developing chicken embryos at optimal temperature 34 C, it shows temperature-sensitivity and cold-adaptation. Strain inherited two genes encoding surface proteins (hemagglutinin and neuraminidase) from epidemic virus and six genes encoding nonglycosylated proteins from attenuation donor. Strain A/17/Nanchang/95/4 (H3N2) is nonreactive for adults at intranasal administration and corresponds to immunogenicity indices. Vaccine strain A/17/Nanchang/95/4 (H3N2) by biological properties and nonreactivity indices corresponds to requirements for vaccine strains by Pharmacopoeia article FS 42-299 VS-89 for living antiinfluenza vaccine for intranasal use for adults. EFFECT: strain indicated above. 1 tbl, 1 ex

Description

 The invention relates to medical virology and can be used in healthcare for the prevention of epidemic influenza among adults with a live intranasal influenza vaccine from strain A / 17 / Nanchang / 95/4 (NZN2). The known vaccine strain 17 / F of influenza A virus (HZN2) - prototype [1] - has lost antigenic relevance and as a result will not be able to cause a protective reaction during an influenza epidemic caused by a strain similar to influenza A / Nanchang / 933/95 (HZN2) .

 The problem to which the invention is directed, is to obtain a vaccine strain of the actual antigenic variety based on the epidemic virus A / Nanchang / 933/95 (HZN2).

 Vaccine strain A / 17 / Nanchang / 95/4 (НЗN2) was obtained by genetic reassortment of the epidemic virus A / Nanchang / 933/95 (НЗN2) with a cold-adapted strain A / Leningrad / 134/17/57 (H2N2) - an attenuation donor - from subsequent selection in the presence of antisera to the virus A / Leningrad / 134/17/57 (H2N2). The attenuation donor is a cold-adapted temperature-sensitive strain of influenza virus A / Leningrad / 134/17/57 (H2N2), approved for the production of harmless live intranasal vaccines for adults [2].

Using restriction analysis of DNA copies of vaccine and parental strains, it was found that vaccine strain A / 17 / Nanchang / 95/4 (НЗN2) inherited 6 genes encoding internal proteins (PB1, PB2, PA, NP, M, NS) from an attenuation donor A / Leningrad / 134/17/57 (H2N2), and 2 genes encoding surface proteins - HA (hemagglutinin) and NA (neuraminidase) - from the epidemic virus A / Nanchang / 933/95 (HZN2). Hemagglutinin in rtga is identical to virus A / Nanchang / 933/95 (HZN2), the antiserum of which is completely neutralized. The strain is temperature-sensitive (the difference in the rate of infectious activity at 34 ^o C and 40 ^o C is 8.0 lg EID ₅₀ / 0.2 ml) and cold-adapted (the difference in the rate of infectious activity at 34 ^o C and 25 ^o C is 3.0 lg EID ₅₀ / 0.2 ml).

 Thus, the presented vaccine strain A / 17 / Nanchang / 95/4 (HZN2) is characterized by a combination of useful features necessary for the vaccine strain: the antigenic specificity of the surface proteins of the epidemic virus A / Nanchang / 933/95 (HZN2), the genome structure optimal for reassortant vaccine strains, temperature sensitivity and cold adaptation, which correlates with attenuation for a person characteristic of an attenuation donor.

 The morphology of the strain is polymorphic, typical of the influenza virus.

STRAIN CHARACTERISTIC
Infectious activity during reproduction in developing chicken embryos at 34 ^o C for 48 hours - 8.5 lg EID ₅₀ / 0.2 ml

 Hemagglutinating activity -1: 256-1: 512.

 The strain exhibits genetic stability of biological traits after 5 passages on chicken embryos (when using large infectious doses).

The data from the passport for the vaccine strain A / 17 / Nanchang / 95/4 (HZN2) are given below:
1. The name of the strain is A / 17 / Nanchang / 95/4 (HZN2)
2. Series - Series 1
3. The method of production and characterization of parent viruses when presenting a recombinant strain: recombination
a). epidemic virus - A / Nanchang / 933/95 (HZN2)
b) attenuation donor - A / Leningrad / 134/17/57 (H2N2)
4. The number of passages - 5 in the process of recombination
5. Characterization of the strain before lyophilization:
a). optimal conditions for reproduction - 34 ^o C, 48 hours;
b) hemagglutinating activity - 1: 256;
in). infectious activity - 8.5 lg EID ₅₀ / 0.2 ml;
d). sensitivity to inhibitors - inhibitory-sensitive;
e). the difference in the indicators of infectious activity at 34 ^o C and 40 ^o C - 8.0 lg EID ₅₀ / 0.2 ml;
e). the difference in the indicators of infectious activity at 34 ^o C and 25 ^o C is 3.0 lg EID ₅₀ / 0.2 ml.

g). recombinant genome structure:
- genes from an epidemic virus - HA, NA
- genes from an attenuation donor - PA, PB1, PB2, NP, M, NS
6. Characterization of the strain after lyophilization:
a). lyophilization date - July 08, 1996;
b) the volume of material in the ampoule is 1 ml;
in). the number of doses in the series - 3;
d). infectious activity - 7.5 lg EID ₅₀ /0.2 ml;
e). hemagglutinating activity -1: 128.

 7. The recommended dilution for vaccination is 1: 3.

8. Antigenic specificity
a). hemagglutinin in rtga - identical to virus A / Nanchang / 933/95 (HZN2), the antiserum of which is completely neutralized;
b) neuraminidase - identical to A / Nanchang / 933/95 (H3N2) virus according to restriction analysis of DNA copies of genes.

 9. Harmless to mice by subcutaneous administration - harmless.

10. Bacteriological control of lyophilized material:
Date - July 1, 1996
the result is sterile.

 11. Control for the absence of extraneous viruses - extraneous viruses are absent.

 Strain A / 17-Nanchang / 95/4 (H3N2) are aretogenic and immunogenic for the adult population.

Example. When vaccinating 92 adults with the intranasally recombinant vaccine strain A / 17 / Nanchang / 95/4 (HZN2) with an infectious activity of 7.5 lg EID ₅₀ / 0.2 ml at a dilution of 1: 2 in a volume of 0.5 ml of strong temperature reactions with an increase in temperature above 38.5 ^o C was not observed. Medium reactions with a short-term increase in temperature in the range of 37.6-38.5 ^o C were observed in 2.2%. Weak temperature reactions (up to 37.5 ^o C) was not. The reactogenicity index (the difference in the percentage of average reactions in vaccinated vaccines and received placebo) was 0%.

 In the group of 77 individuals who received a placebo, average temperature reactions were observed in 6.5%, weak reactions were also observed in 6.5% of cases (Table 1).

 Thus, the vaccine strain A / 17 / Nanchang / 95/4 (HZN2) in terms of reactogenicity meets the requirements of pharmacopoeial article FS 42-299 BC-89 for vaccine strains for live influenza vaccine for intranasal use for adults.

 Sources of information.

 1. Strain 17 / F of influenza A virus (H3N2) used to obtain a live intranasal vaccine for adults. Author's certificate N 1222276. Published 07.04.86, BI N 13.

 2. Alexandrova G.I., Klimov A.I. Live flu vaccine. -SPb .: Nauka, 1994, p. 151.

Claims (1)

 The strain of influenza virus A / 17 / Nanchang / 95/4 (NZN2) GISK N 1001 (State Institute of Standardization and Control named after L.A. Tarasevich), used to obtain a live influenza intranasal vaccine for adults.

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