quadrivalent inactivated split influenza vaccine

**Quadrivalent inactivated split influenza vaccine** is an injectable vaccine containing inactivated and purified antigens from four influenza virus strains: two influenza A subtypes (H1N1, H3N2) and two influenza B lineages (Victoria and Yamagata)[1][2][3][5][6]. The vaccine is produced by growing the viruses in embryonated eggs, inactivating with formaldehyde, and disrupting the viral particles with detergents (e.g. Triton X-100 or sodium deoxycholate), resulting in "split virion" antigens. After injection, the vaccine induces a protective humoral immune response by eliciting the production of antibodies against viral haemagglutinins, which can neutralize circulating influenza viruses and prevent illness. Strains are updated annually according to WHO recommendations to match prevalent circulating viruses[2][3][5][6]. Commonly used for active immunization in children and adults, including pregnant women, and for passive immunization of infants born to vaccinated mothers[1].

Brand names

Fluzone QuadrivalentFluarix QuadrivalentFlulaval TetraAfluria Quadrivalent

Other names

quadrivalent split-virion inactivated influenza vaccinequadrivalent inactivated influenza vaccineIIV4IIV-4IIV 4