title: Vaccines: how, why, and when?
mesh_terms: D000367:Age Factors; D001428:Bacterial Vaccines / Q000276:immunology*; D001694:Biological Warfare; D006801:Humans; D007111:Immunity, Cellular; D007252:Influenza Vaccines / Q000276:immunology; D007251:Influenza, Human / Q000517:prevention & control; D008214:Lymphocytes / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D001428:Bacterial Vaccines; D007252:Influenza Vaccines; D014765:Viral Vaccines