Fluenz Tetra

Fluenz Tetra is a quadrivalent live attenuated influenza vaccine (LAIV) administered as an intranasal spray for the prevention of seasonal influenza. Developed by AstraZeneca (via its subsidiary MedImmune), it contains four cold-adapted, temperature-sensitive influenza virus strains (two Type A and two Type B) that are designed to replicate in the cooler environment of the nasopharynx but not in the lungs. This replication induces a broad immune response, including mucosal IgA, systemic IgG, and T-cell mediated immunity, mimicking natural infection without causing the disease. The vaccine is primarily indicated for children and adolescents. The SNIFFLE-4 study, a Phase 4 trial conducted by Imperial College London in collaboration with Public Health England, specifically assessed the safety and tolerability of the 2016/2017 formulation in children with moderate to severe asthma or recurrent wheeze, demonstrating that the vaccine is well tolerated in this population.

Brand names

Fluenz TetraFluMist Quadrivalent

Other names

LAIVLive Attenuated Influenza VaccineLAIV4LAIV-4LAIV 4Quadrivalent Live Attenuated Influenza Vaccine