ATTENUATED TS-RECOMBINANTS OF INFLUENZA A/USSR/77 (H1N1) VIRUS OBTAINED BY CROSSING WITH THE COLD-ADAPTED DONOR A/LENINGRAD/134/57 (H2N2) VIRUS

Abstract

Conditions for obtaining attenuated influenza virus recombinants by crossing a cold-adapted donor with A (H1N1) influenza virus that reappeared in 1977 were studied. Temperature-sensitive recombinants suitable for intranasal immunization of adults with low titers of anti-hemagglutinin and anti-neuraminidase antibodies, and possessing sufficiently high immunogenicity, were obtained by crossing of native parent strains and cross-reactivation techniques. It was confirmed that the cold-adapted A/Leningrad/135/17/57 (H3N2) influenza virus variant is a prospective donor of attenuation for obtaining recombinants, candidates for live influenza vaccine strains.