The influence of seasonal influenza viruses biological features on the effectiveness of development strains for live influenza vaccine

Aim . Evaluation of the efficiency of the method of reassortant strains for live influenza vaccine development and ways to optimize it, taking into account the differences in the current epidemic influenza viruses by key biological characteristics. Materials and methods . Influenza viruses — candidates for seasonal LAIVs, MDVs for Russian LAIVs A/Leningrad/134/17/57 (H2N2) and B/USSR/60/69. The vaccine strains development in developing chicken embryos included reassortment, selective passages at low temperature in the presence of hyperimmune serum to the MDV, several stages of reassortants cloning, their virological and molecular genetic characteristics. Epidemic influenza viruses and LAIVs strains were evaluated by their ability to reproduction at temperatures beyond optimal values, by sensitivity to serum inhibitors. Results . The assessment of phenotypic properties used in reassortment epidemic viruses is carried out. Presented the data on the efficiency of development reassortant strains for LAIV depending on the biological properties of circulating epidemic influenza viruses: their temperature-resistant, cold-sensitive phenotype, inhibitor resistance, and receptor specificity. Conclusion . Based on the assessment of the influence of the biological characteristics of the epidemic viruses, the rational methodological techniques for the most effective development of reassortants for LAIV are selected.