[Dinamics in virulence of highly pathogenic influenza A virus A/H5N1 genotype 2.2 strains isolated in Russia in 2005-2007].

: In 2005 to 2007, there was a reduction in the virulence of highly pathogenic avian influenza A virus A/H5N1 genotype 2.2 strains deposited in the State Collection of Viruses of the Russian Federation. Decreased virulence was most marked in the strains from domestic birds, the least in those from wild birds. Comparison of phenotypical and molecular genetic data revealed point amino acid replacements that might affect reduced virulence.