FDA panel backs Moderna’s mRNA flu vaccine for older adults

Federal vaccine advisers gave Moderna’s flu shot a clear boost on June 18, unanimously backing the company’s mRNA vaccine for adults 50 and older and setting up a final FDA decision by August 5. If approved, MFLUSIVA would become the first influenza vaccine built on the same mRNA platform that powered the COVID-19 shots.

The appeal of mRNA is speed. Flu vaccines are harder to make than COVID-19 vaccines in one important way: manufacturers have to guess months ahead which strains will dominate, then build the seasonal formula before the virus has finished evolving. Moderna told advisers its platform could be produced faster than traditional shots, which matters if a strain changes after the recipe is set. That flexibility could give public-health officials another tool when the annual vaccine match is imperfect.

The company’s main evidence came from P304, a phase 3 trial that enrolled 40,805 adults across 11 countries. Moderna said mRNA-1010 delivered 26.6% relative vaccine efficacy versus a licensed standard-dose comparator in adults 50 and older, and 27.4% in participants 65 and older. The results were published in the New England Journal of Medicine. In a smaller study of older adults, the vaccine also generated a strong immune response compared with a high-dose shot already recommended for that age group.

Safety was central to the discussion, and Moderna said most solicited adverse reactions in the phase 3 study were mild. Advisers concluded the benefits outweighed the risks in both age bands, 50 to 64 and 65 and older. That matters because the FDA had initially refused to review Moderna’s application in February 2026 before reversing course about two weeks later, and this meeting was the agency’s first review of a new vaccine application since 2023.

The bigger question is not whether mRNA can work, but whether it can improve yearly flu protection or simply add another option. For now, the answer looks closer to the second. CDC guidance for the 2025-26 season says flu vaccination remains recommended for everyone 6 months and older, with as many as 154 million doses in supply and trivalent formulations standard. Adults 65 and older are still steered toward high-dose, adjuvanted or recombinant vaccines, while Moderna is aiming for the 2026-27 season and faces entrenched rivals including Sanofi, GSK, CSL Seqirus and AstraZeneca. The panel’s vote shows mRNA is moving beyond COVID, but not yet displacing the established flu market.