[Use of monoclonal antibodies for the antigenic analysis of the hemagglutinin of influenza viruses (H3N2) isolated in the USSR in 1979-1980].

Monoclonal antibodies for the A/England/864/75 strain hemagglutinin were used for antigenic analysis of influenza A (H3N2) viruses isolated in the USSR in December 1979--January 1980. The results of studies with 5 different monoclones were compared with those obtained with postinfection ferret sera. It was shown that several variants of epidemic strain could circulate during one epidemic season. The epidemic in the USSR in December, 1979--January 1980 was caused by influenza viruses H3N2 similar to A/Texas/1/77 as well as further driftstrains. Four epidemic strains were circulating which differed by the composition of antigenic determinants of hemagglutinin. Members of the first group shared 4 out of 5 determinants with A/England/864/75 strains, the second group differed by two monoclones and was identical with the A/Texas/1/77 strain. The third group differed in 3 determinants and was similar to the A/Bangkok/1/79 strain, the fourth group was related to the A/England/864/75 strain only by one out of five clones. The method of monoclonal antibodies was shown to be highly sensitive and could be satisfactorily used for subtle antigenic analysis of influenza viruses.