title: Evolution of pandemic influenza virus strains.
mesh_terms: D000954:Antigens, Surface / Q000235:genetics; D000956:Antigens, Viral / Q000235:genetics; D005075:Biological Evolution; D005814:Genes, Viral; D006023:Glycoproteins / Q000235:genetics; D006389:Hemagglutinins, Viral / Q000235:genetics; D009980:Influenza A virus / Q000235:genetics*; D009439:Neuraminidase / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology
chemical_list: D000954:Antigens, Surface; D000956:Antigens, Viral; D006023:Glycoproteins; D006389:Hemagglutinins, Viral; D012367:RNA, Viral; D014764:Viral Proteins; D009439:Neuraminidase