Flu vaccine

特許 係属中 The influenza vaccine, also known as flu shot, is an annual vaccination using a vaccine that is specific for a given year to protect against the highly variable influenza virus.[1] Each seasonal influenza vaccine contains antigens representing three (trivalent vaccine) or four (quadrivalent vaccine) influenza virus strains: one influenza type A subtype H1N1 virus strain, one influenza type A subtype H3N2 virus strain, and either one or two influenza type B virus strains.