title: The meaning of the appearance of Hong Kong influenza.
mesh_terms: D000367:Age Factors; D000368:Aged; D000906:Antibodies; D000941:Antigens / Q000032:analysis*; D014644:Genetic Variation; D006723:Hong Kong; D006801:Humans; D007251:Influenza, Human / Q000276:immunology*; D008875:Middle Aged; D009975:Orthomyxoviridae / Q000276:immunology; D012699:Serology
chemical_list: D000906:Antibodies; D000941:Antigens