 Vaxigrip, a widely used trivalent splitvirian inactivated vaccine available since 1968, has been shown through numerous studies to be effective and safe in preventing influenza in healthy individuals of all ages and at-risk populations. The quadrivalent formulation of Vaxigrip, which contains 2A and 2B influenza strains, Vaxigrip tetra, offers broader protection while maintaining a similar immunogenicity and safety profile to the trivalent formulation. This article was authored by Margaret Haw, Vivian Gresset Bourgeois, Berenger Macabio, and others.