title: Letter: Efficacy of influenza vaccines.
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000453:epidemiology; D007252:Influenza Vaccines / Q000009:adverse effects; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control*; D009975:Orthomyxoviridae / Q000276:immunology; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines