FDA panel backs Moderna's mRNA flu vaccine for adults 50 and older

FDA vaccine advisers gave Moderna a unanimous endorsement for its mRNA flu shot, setting up a possible U.S. first if regulators approve the product. The vote also marks a notable moment for the agency, which has gone without a vaccine recommendation from its advisory panel since 2023.

The FDA’s Vaccines and Related Biological Products Advisory Committee met June 18 to review Moderna’s MFLUSIVA, also called mRNA-1010, for prevention of influenza in people 50 and older. The panel voted 9-0 that the benefits outweighed the risks for adults ages 50 to 64, and 9-0 again for adults 65 and older. For the older group, committee members backed an accelerated-approval route that would require a post-marketing phase 4 study to confirm the vaccine works as expected.

If the FDA follows the committee’s advice, MFLUSIVA would become the first mRNA-based seasonal flu vaccine in the United States. The decision also serves as a test of whether the agency is moving back toward a more traditional vaccine-review process after recent leadership turnover.

Moderna says the FDA’s Prescription Drug User Fee Act goal date is August 5, 2026. The application reached the review stage only after an earlier setback: on February 10, the FDA issued a refusal-to-file letter and said it would not begin reviewing Moderna’s biologics license application for the investigational vaccine, mRNA-1010. The company later said the agency agreed to review an amended filing after a Type A meeting.

The committee’s backing rested on Moderna’s Phase 3 P304 trial, which enrolled 40,805 adults 50 and older across 11 countries. Moderna said the vaccine showed 26.6% relative efficacy versus a licensed standard-dose flu shot overall, and 27.4% relative efficacy in adults 65 and older. The company also said the trial showed strain-specific efficacy against A/H1N1, A/H3N2 and B/Victoria lineages, with a safety profile consistent with earlier studies.

The advisory panel’s vote is non-binding, and the FDA will make the final decision. If the agency grants approval, Moderna would secure a milestone that has been years in the making: a seasonal flu shot built on the mRNA platform that reshaped vaccine development during the pandemic.