title: [New antigenic variants of influenza A(H1N1) virus detected in the USSR in 1979].
abstract: Studies of influenza A (H1N1) viruses isolated in the spring of 1979 in the USSR showed all the 73 strains to belong to influenza A (H1N1) virus but to be heterogeneous. Apart from the strains identical with the reference A/USSR/90/77 and A/Brazil/11/78 as well as intermediate ones, 14 strains were identified and found to be new drift variants. A composite analysis of representative strains of this group (A/USSR/50/79 and A/USSR/61/79) by HI test with diagnostic rat and ferret sera as well as monoclonal antibody and by immunoadsorption method confirmed their individual natures and showed them not to be identical completely to any one of the previously known drift variants of the A (H1N1) subtype. The neuraminidase of the new strains also acquired some changes in the antigenic composition and resistance to detergents destroying disulfide bonds indicating certain alterations in this subunit as well. Besides, a comparison of the drift variants of influenza A (H1N1) virus variants isolated in 1947-1957 and in 1977-1979 showed the drift of the new A (H1N1) strain to occur in a different way than in those isolated in 1947-1957.
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000032:analysis*; D000939:Epitopes / Q000032:analysis; D006389:Hemagglutinins, Viral / Q000032:analysis; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D009980:Influenza A virus / Q000276:immunology / Q000302:isolation & purification*; D007251:Influenza, Human / Q000382:microbiology*; D009439:Neuraminidase / Q000032:analysis; D051381:Rats / Q000276:immunology; D012703:Serotyping; D014586:USSR
chemical_list: D000956:Antigens, Viral; D000939:Epitopes; D006389:Hemagglutinins, Viral; D009439:Neuraminidase
vernacular_title: Novye antigennye varianty virusa grippa A(H1N1) obnaruzhennye v SSSR v 1979 g.