title: Swine influenza viruses isolated in 1976 from man and pig contain two coexisting subpopulations with antigenically distinguishable hemagglutinins.
mesh_terms: D000818:Animals; D003429:Cross Reactions; D000939:Epitopes; D005796:Genes; D006385:Hemagglutination Inhibition Tests; D006389:Hemagglutinins, Viral; D006801:Humans; D009980:Influenza A virus / Q000201:enzymology / Q000276:immunology*; D009439:Neuraminidase / Q000032:analysis; D011995:Recombination, Genetic; D013552:Swine / Q000382:microbiology
chemical_list: D000939:Epitopes; D006389:Hemagglutinins, Viral; D009439:Neuraminidase