title: Evolution and hierarchy of influenza viruses.
mesh_terms: D000906:Antibodies; D000918:Antibody Specificity; D000941:Antigens / Q000032:analysis*; D005075:Biological Evolution; D000939:Epitopes; D007106:Immune Sera; D008954:Models, Biological; D009154:Mutation; D009975:Orthomyxoviridae / Q000145:classification / Q000276:immunology*
chemical_list: D000906:Antibodies; D000941:Antigens; D000939:Epitopes; D007106:Immune Sera