FDA Approves Moderna mFLUVISA: First mRNA Flu Vaccine Clears PDUFA

The FDA approved Moderna’s (MRNA) mFLUVISA on August 5, making it the first mRNA-based seasonal influenza vaccine licensed in the United States. The approval, which arrived on the PDUFA deadline, covers adults 50 to 64 under standard approval and adults 65 and older under accelerated approval. Moderna shares closed at $56.26 on August 5, roughly flat on a day when the broader market had already priced in the decision following the 9-0 advisory committee vote in June.

The approval validates a platform searching for a second commercial product beyond Spikevax. mFLUVISA’s Phase 3 data showed a 26.6% relative vaccine efficacy advantage over standard-dose flu vaccines (95% CI, 16.7% to 35.4%), meeting prespecified criteria for both noninferiority and superiority. The trial enrolled roughly 73,000 participants across multiple hemispheres, making it one of the largest influenza vaccine efficacy studies ever conducted. The VRBPAC had voted unanimously in favor on June 18.

As an mRNA vaccine, mFLUVISA offers faster strain matching than egg-based or cell-based manufacturing. A flu shot can be designed and produced in weeks rather than months, a feature that matters when the circulating strain drifts mid-season. The commercial question is whether that advantage translates to market share in a roughly $7 billion global flu vaccine market dominated by Sanofi’s Fluzone franchise, GSK’s Fluarix, and CSL Seqirus’ Flucelvax, each of which holds multi-year contracts with pharmacy chains and health systems.

The split label reflects two distinct evidence packages. The standard approval for adults 50 to 64 rests on the full efficacy dataset. The accelerated approval for adults 65 and older comes with a post-marketing requirement for confirmatory data, a condition that could shape how the CDC’s Advisory Committee on Immunization Practices (ACIP) evaluates mFLUVISA for the 2026-27 flu season.

What to watch next: the ACIP recommendation. Even with an FDA approval, the CDC’s advisory committee decides whether mFLUVISA joins the annual flu vaccine roster on equal footing with established products. That vote, expected in the coming months, will determine whether Moderna gets a real commercial launch or a technical approval with no distribution channel.

The flu approval also strengthens the case for Moderna’s combination vaccine pipeline: flu-COVID and flu-RSV shots that would let the company compete on convenience rather than efficacy alone. Each mRNA approval that clears regulatory review makes the platform argument harder to dismiss. Moderna’s market cap stands at roughly $21 billion, and the stock has been range-bound near $57 as investors wait for revenue diversification to materialize.