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

The U.S. Food and Drug Administration approved Moderna’s mFLUSIVA (mRNA-1010), the first mRNA-based seasonal influenza vaccine, for adults 50 years and older. The decision follows a phase 3 trial of more than 40,000 participants in 11 countries, which showed the vaccine was about 27% more effective at preventing laboratory-confirmed influenza than a standard-dose egg-based flu shot, with no new safety concerns identified.

The agency granted traditional full approval for people aged 50-64 and accelerated approval, pending further post-marketing data, for those 65 and older. Moderna expects the product to be on the U.S. market for the 2026-2027 respiratory virus season.

"An important addition to our influenza prevention toolkit, particularly because adults over 50 begin to experience a progressively higher risk of serious complications from influenza," said Dr. Dung Trinh, internist and chief medical officer of Healthy Brain Clinic.

"The FDA approval of Moderna’s mFLUSIVA is scientifically interesting and potentially important, but I would not interpret it as proof that the mRNA vaccine is necessarily the best flu vaccine for every person over 50," said Dr. David Cutler, family-medicine physician at Providence Saint John’s Health Center.

Experts noted that mRNA technology can be manufactured more quickly than traditional egg-based vaccines, potentially allowing a better match to rapidly evolving flu strains. The vaccine’s side-effect profile in trials included common reactions such as headache, fatigue, muscle and joint pain, fever and injection-site soreness, with rare reports of severe allergic reactions.

Health officials emphasized that the new option should complement, not replace, existing flu vaccines, and advised individuals to consult their healthcare providers about suitability, especially those with a history of severe vaccine reactions, immunocompromising conditions, or pregnancy.