[COLD-ADAPTED A/KRASNODAR/101/35/59 (H2N2) STRAIN--A PROMISING STRAIN-DONOR OF ATTENUATION FOR PROCURATION OF LIVE INFLUENZA VACCINES]

Abstract

Aim: Study of ts, ca, att phenotype, immunogenicity and protective effectiveness of reassortants obtained by a way of recombination of a new influenza cold-adapted (ca) strain donor of attenuation A/Krasnodar/101/35/59 (H2N2) and virulent strain of influenza virus.

Materials and methods: Viruses were used: ca strain A/Krasnodar/101/35.59 (H2N2), virulent strains: A/Kumamoto/102/02 (H3N2) and A/Bern/07/95. For determination of ts and ca phenotype, titration of viruses in chicken embryos was carried out simultaneously at optimal, decreased and increased temperature. Protective effect of immunization was evaluated during intranasal infection of mice with a virulent strain of influenza virus.

Results: All the obtained reassortants possessed 6 internal genes from strain-donor of attenuation and 2 genes, coding HA and NA-proteins from virulent strains. Ca reassortants were characterized by ts and ca phenotype, had antigenic specificity and good immunogenicity, had high protective effectiveness.

Conclusion: The data obtained indicate on the perspectiveness of ca strain A/Krasnodar/101/35/59 (H2N2)as a donor of attenuation for live influenza vaccines.