title: Antigenic similarity of influenza A (H1N1) viruses from epidemics in 1977--1978 to "Scandinavian" strains isolated in epidemics of 1950--1951.
mesh_terms: D000956:Antigens, Viral / Q000032:analysis*; D004196:Disease Outbreaks; D000939:Epitopes; D006385:Hemagglutination Inhibition Tests; D006389:Hemagglutinins, Viral / Q000276:immunology; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D009980:Influenza A virus / Q000276:immunology*; D007251:Influenza, Human / Q000382:microbiology*; D009439:Neuraminidase / Q000276:immunology
chemical_list: D000956:Antigens, Viral; D000939:Epitopes; D006389:Hemagglutinins, Viral; D009439:Neuraminidase