FluMist Quadrivalent (MedImmune)

FluMist Quadrivalent is a live-attenuated influenza vaccine (LAIV) developed by MedImmune, a subsidiary of AstraZeneca. It is designed for intranasal administration and provides active immunization against four different influenza virus strains: two influenza A subtypes (H1N1 and H3N2) and two influenza B lineages (Victoria and Yamagata). Unlike inactivated vaccines, FluMist contains cold-adapted, temperature-sensitive viruses that replicate in the cooler environment of the nasopharynx but are restricted from replicating in the warmer lower respiratory tract. This mechanism induces a broad immune response, including mucosal IgA production in the nasal passages, systemic neutralizing antibodies, and cellular immune responses, mimicking a natural infection. It is typically indicated for individuals aged 2 through 49 years.

Brand names

FluMist QuadrivalentFluenz Tetra

Other names

Live Attenuated Influenza Vaccine QuadrivalentInfluenza Vaccine Live Intranasal QuadrivalentMED-I0159MED-I-0159MED-I 0159