The U.S. Food and Drug Administration has approved mFLUSIVA, a seasonal influenza vaccine from Moderna that uses messenger RNA technology, the company announced Wednesday. It is the first mRNA-based flu vaccine to receive FDA approval.
The vaccine is approved for adults ages 50 and older. The agency granted full approval for the 50–64 age group and accelerated approval for people 65 and older, which requires Moderna to conduct an additional study in that population.
The decision followed a regulatory dispute earlier this year. In a refusal-to-file letter, FDA vaccine director Dr. Vinay Prasad said a 40,000-person clinical trial did not include a comparator vaccine specifically recommended for adults 65 and older.
Moderna subsequently amended its application, narrowing the full-approval request to ages 50–64 and seeking accelerated approval for the older group, while agreeing to run the required post-marketing study. The FDA accepted the revised application about a week after its initial refusal.
The approval occurred despite public criticism of mRNA technology by Health and Human Services Secretary Robert F. Kennedy Jr., who last year canceled 22 mRNA vaccine development projects. The FDA is part of HHS.
Moderna said it expects mFLUSIVA to be available for the 2026–27 flu season. The company stated the approval reflects the potential of its mRNA platform to address public health challenges through continued scientific innovation.
The pivotal trial found the vaccine was more effective than one standard flu shot in adults 50 and older, though the initial submission did not compare it against the high-dose or adjuvanted vaccines preferentially recommended for seniors.
Regulators will review data from the additional study in older adults as a condition of the accelerated approval pathway.
FDA approves Moderna's mRNA flu vaccine after initial pushback
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