influenza virus vaccine, split virion, inactivated

The **influenza virus vaccine, split virion, inactivated** is an injectable vaccine containing inactivated and “split” viral particles from selected influenza virus strains. The “split” refers to viral particles that have been disrupted by detergents after inactivation—removing much of the viral RNA and reducing reactogenicity compared to whole-virus vaccines. The vaccine is typically quadrivalent, containing two influenza A subtypes (such as H1N1 and H3N2) and two influenza B lineages (typically Victoria and Yamagata); some formulations may be trivalent. It acts by inducing humoral immune responses—specifically antibodies against the influenza virus haemagglutinin and, to a lesser extent, neuraminidase surface antigens. Antibodies produced provide protection against the virus strains contained in the vaccine. Immunity usually develops within 2–3 weeks after vaccination. The vaccine is recommended for annual administration due to antigenic drift in circulating influenza viruses. Its primary indication is the prevention of influenza infection in adults, children from 6 months of age, pregnant women, and for passive neonatal protection through maternal immunization[1][4][5].

Brand names

Fluzone High-Dose QuadrivalentFluvaxInfluvacAgrippalFluviralVaxigripQuadrivalent Influenza Vaccine (split virion, inactivated)

Other names

inactivated split-virion influenza vaccinesplit-virus influenza vaccineinactivated influenza vaccine (split virion)split influenza vaccine