FluMist Quadrivalent

FluMist Quadrivalent is a live attenuated influenza vaccine (LAIV) developed by MedImmune (now a part of AstraZeneca). Unlike traditional injectable vaccines, it is administered as an intranasal spray. The vaccine contains four strains of influenza virus: two influenza A subtypes (H1N1 and H3N2) and two influenza B lineages (Victoria and Yamagata). These viruses are cold-adapted and temperature-sensitive, allowing them to replicate in the cooler environment of the nasopharynx to induce mucosal and systemic immunity, while preventing replication in the warmer lower respiratory tract. It is indicated for the active immunization of individuals aged 2 through 49 years for the prevention of influenza disease caused by the specific strains contained in the vaccine. The formulation is updated annually to match the strains recommended by public health authorities.

Brand names

FluMistFluMist QuadrivalentFluenzFluenz Tetra

Other names

Live Attenuated Influenza VaccineLAIVLAIV4LAIV-4LAIV 4MedImmune influenza vaccineInfluenza Vaccine Live Intranasal