Highly reproductive attenuated H2N2 and H7N9 reassortants on the basis of A/Hong Kong/1/68/162/35 donor virus.

Reassortants with surface antigens from potentially pandemic A/H2N2 and A/H7N9 influenza viruses were created on the basis of attenuated and highly reproductive A/Hong Kong/1/68/162/35(H3N2) donor virus obtained in the Research institute of influenza. High reproductive activity of reassortant viruses and immunogenicity of live and inactivated influenza vaccines based on these viruses indicate the possibility to use obtained reassortants for production of live and inactivated vaccines against potentially pandemic influenza A viruses.

[Immunization with live attenuated A/H5N1 vaccine protects guinea pigs from reinfection].

Cold-adapted influenza virus A/HK/1/68/162/35(H3N2) was developed as unified donor of attenuation and high reproductive capacity forvaccine strains. The reassortant of this donor with surface antigens of highly pathogenic strain Alchicken/Astana/6/05 (H5N1) was tested in guinea pigs as a live or inactivated preparation. Immunization with both formulations induced equal levels of serum virus specific antibodies, while the level of mucosal antibodies was significantly higher in animals immunized with live virus.

Study of immunogenicity of recombinant proteins based on hemagglutinin and neuraminidase conservative epitopes of influenza A virus.

Background: Recombinant hemagglutinin (rHA) and neurominidase (rNA) developed in our investigation are amino acid sequence consensus variants of H1N1 2009 subtype influenza virus strain, also including immunogenic epitopes typical for other influenza virus subtypes (H3N1 and H5N1). Substitutions were made: typical for Russian virus isolates (in HA - S220T, NA - D248N) and in active centers of molecules - R118L, R293L, R368L; C92S, C417S to increase recombinant proteins stability in E. coli.

[Characterization of influenza virus reassortants based on new donor strain A/HK/1/68/162/35(H3N2)].

Influenza reassortant viruses A/SPb/HK/09(H1N1), A/Astana/HK/2009 (H5N1), A/Otar/HK/2010(H3N8), and A/Perth/ HK/2011(H3N2), carrying surface antigens of different subtypes, were constructed on the basis of new potential unified donor strain A/HK/1/68/162/35(H3N2). The virulence and reproduction activity of the obtained reassortants were tested. The safety of the candidate live and inactivated influenza vaccines produced from the reassortant viruses was demonstrated.

[Characterization of cold-adapted influenza strain A/HongKong/1/68/162/35 as a potential donor of attenuation and high reproduction].

Live and inactivated vaccines are currently produced using virus reassortants originating from various gene donors of internal proteins. Based on the pandemic virus A/Hong Kong/1/68 (H3N2), a cold-adapted thermo-sensitive strain A/Hong Kong/1/68/162/35 was generated. It is distinguished for its high reproductive capacity (9-9.