FDA Advisory Committee Votes Unanimously to Recommend Moderna’s mRNA Flu Vaccine

1. The FDA’s top vaccine advisory committee voted 9-0 on June 18, 2026 to recommend Moderna’s mRNA influenza vaccine mFlusiva for adults 50 and older, setting up what could be the first mRNA-based seasonal flu vaccine ever approved in the United States by August 5.

2. The unanimous vote followed an unusual regulatory reversal earlier this year, but a legal dispute over the CDC’s immunization advisory committee means approval and actual patient access may not happen on the same schedule.

It has been a strange year for Moderna’s mRNA flu vaccine. In February 2026, then-CBER director Vinay Prasad issued a rare refusal-to-file letter arguing that Moderna should have used a high-dose rather than standard-dose comparator in its pivotal trial. The FDA reversed that decision within days after widespread public criticism. Both Prasad and former commissioner Marty Makary have since left the agency. On June 18, 2026, the VRBPAC voted 9 to 0 twice, once for adults aged 50 to 64 and once for adults 65 and older, that the benefits of mFlusiva outweigh its risks. It was the committee’s first review of a new vaccine application since May 2023. The pivotal phase 3 efficacy data, published in the New England Journal of Medicine, showed a relative vaccine efficacy 26.6% higher than a licensed standard-dose comparator in adults 50 and older over one flu season. FDA staff briefing documents ahead of the meeting raised legitimate concerns: the efficacy data spans only one season, frail older adults and immunocompromised patients were not well characterized in the subgroup analyses, and the efficacy against influenza B strains was not definitively established. The panel found none of those gaps sufficient to recommend against approval. The CDC presented data to the committee that framed the stakes: the 2025 to 2026 flu season produced at least 32 million infections, 390,000 hospitalizations, and 24,000 deaths in the United States, with approximately 85% of eligible individuals not fully vaccinated. The technical argument for the mRNA platform in influenza is not primarily about efficacy of the vaccine in hand, though the data are positive. It is about what the platform enables going forward. Current flu vaccine production requires strain selection roughly six months before the season begins, and egg-based manufacturing can introduce mutations that reduce match accuracy. As BioPharma Dive reported following the vote, the mRNA manufacturing process could compress that timeline to two to three months, improving the probability that the vaccine matches the circulating strain in any given year. That flexibility also makes the platform more valuable in the event of a pandemic flu strain. The FDA’s final decision is expected by August 5, 2026. Getting that approval is the first hurdle. Patient access requires a second step: a CDC Advisory Committee on Immunization Practices recommendation, which is what triggers insurance coverage requirements under the Affordable Care Act. The ACIP is currently under legal challenge related to membership changes made by HHS Secretary Robert F. Kennedy Jr., and whether it has the legal standing to convene and issue a recommendation before the fall flu season begins is genuinely uncertain. Clinicians should continue advising eligible patients to get a flu vaccine this fall with whatever options are available, while monitoring whether mFlusiva becomes accessible and covered in time to add it as a choice for adults 50 and older.