[Evolution of influenza A(H3N2) virus from 2007 to 2012].

The results of the genetic studies of influenza viruses make it possible to understand their evolution and recommendations for vaccine strains content. In this work, the data of complete sequence of the HA, NA, and M2-protein for 34 strains of influenza A(H3N2) virus circulating in Russia during 2007-2012 are presented. The influenza strains were isolated in Ivanovsky Institute of Virology, Moscow, and some collaborating Russian centers. The results of the phylogenetic analysis showed the differences among strains, which were observed during the analyzed period; the evolution had direction from A/Brisbane/10/2007 to A/Perth/16/2009 and A/ Victoria/208/2009. Hemagglutinin of the influenza A(H3N2) virus strains had differences between strains of last two seasons and strains circulating before, in the antigenic sites A, B, D, and, to a lesser extent, C, and E. In the neuraminidase gene the mutations responsible for the resistance to oseltamivir (E119V, R292K, N294S) and zanamivir (Q136K) were not found. All isolates carry the S31N mutation in the M2 gene responsible for resistance to amantadine.