influenza vaccine (inactivated)

Seasonal IIV (Seasonal Inactivated Influenza Vaccine) is a study-specific designation used in clinical research, notably by the University of Rochester (e.g., NCT02559505), to refer to standard-of-care inactivated influenza vaccines. In the context of these pediatric studies, Seasonal IIV specifically identifies Fluzone (manufactured by Sanofi Pasteur), which is administered in trivalent or quadrivalent formulations. The vaccine consists of split-virus inactivated influenza antigens, primarily hemagglutinin (HA) and neuraminidase (NA), derived from circulating seasonal influenza A (H1N1 and H3N2) and B (Victoria and Yamagata lineages) strains. Its mechanism of action involves stimulating the host's immune system to produce virus-specific antibodies and CD4+ T-cell responses, thereby providing protection against seasonal influenza infection. Research utilizing this label often investigates how the initial mode of influenza exposure—whether through natural infection or vaccination—influences the immune system's subsequent response to future vaccine challenges.

Brand names

FluzoneFluzone QuadrivalentFluzone Trivalent

Other names

IIVinactivated influenza vaccinesplit-virus inactivated influenza vaccine