VRBPAC Unanimously Endorses Moderna's mRNA Flu Vaccine for Adults 50 and Older

The VRBPAC meeting reviewed immunogenicity and safety data from Phase 3 trials comparing the mRNA construct against licensed quadrivalent inactivated vaccines. Staff presentations indicated the candidate met prespecified criteria for hemagglutination inhibition titers and showed a comparable reactogenicity profile, supporting traditional licensure for the 50-64 cohort and accelerated approval for those 65 and older based on surrogate endpoints.

This endorsement extends the mRNA platform validated during COVID-19 to routine respiratory vaccines. Unlike prior protein-based flu shots, the mRNA approach permits rapid strain updates and potential multivalent formulations targeting influenza plus RSV or SARS-CoV-2. Observational data from mRNA COVID boosters already suggest modest reductions in all-cause respiratory hospitalizations, providing a mechanistic bridge to seasonal flu performance that protein vaccines have not consistently achieved.

The panel's vote leaves open questions on real-world effectiveness against laboratory-confirmed influenza and hospitalization. Post-marketing studies will need to track antigenic drift mismatches and durability beyond one season. Manufacturing consistency at commercial scale also remains a regulatory focus before full rollout.

FDA Commissioner decision is expected within weeks. If approved, initial supply targets 2027 Northern Hemisphere season with emphasis on high-risk groups already recommended for enhanced flu vaccines.