FDA Reverses Course, Accepts Moderna mRNA Flu Vaccine Application for Review

The FDA has agreed to review Moderna's application for what would be the first mRNA-based flu vaccine, reversing a rare refusal to even accept the filing. The agency assigned a Prescription Drug User Fee Act (PDUFA) goal date of August 5, 2026, following a formal Type A meeting with the company.

Moderna proposed a revised regulatory pathway based on age, seeking full approval for adults 50 to 64 years of age and accelerated approval for adults 65 and older, along with a post-marketing requirement to conduct an additional study in older adults. Following submission of the amended application, the FDA accepted the biologics license application (BLA) for review.

"We appreciate the FDA's engagement in a constructive Type A meeting and its agreement to advance our application for review," Moderna chief executive Stéphane Bancel said in a statement. "Pending FDA approval, we look forward to making our flu vaccine available later this year so that America's seniors have access to a new option to protect themselves against flu."

The Department of Health and Human Services confirmed the meeting and said it had accepted Moderna's new approach. "FDA will maintain its high standards during review and potential licensure stages as it does with all products," an HHS spokesman said in a statement.

In early February, Moderna announced that its application for approval of an mRNA-based seasonal influenza vaccine had received a "refuse to file" letter from the FDA. This was not a rejection on scientific grounds after full review but a refusal even to consider the application for formal evaluation. According to reporting, the decision overruled career staff who had recommended proceeding with review and came from leadership within the agency's vaccines division.

The refuse-to-file decision, followed by the reversal, was extraordinary. In economic terms, it is destabilizing. In public health terms, it signals something worse than a single product dispute: a less predictable, politicized system.

Pending review and FDA approval, mRNA-1010 would be available for U.S. adults 50 years of age and older, including adults 65 and older, for the 2026/2027 flu season. The vaccine candidate has now been accepted for review in the United States, Europe, Canada and Australia with further submissions planned in 2026. Moderna expects the first potential approvals for mRNA-1010 in 2026, subject to various ongoing regulatory reviews.

The 2024–2025 flu season killed tens of thousands of Americans — possibly more than 100,000. Hundreds of thousands were hospitalized. The elderly, immunocompromised individuals, children under 5, and people with chronic disease are particularly vulnerable.