FDA to review Moderna's mRNA flu shot, reversing previous decision, company confirms

The U.S. FDA has decided to review Moderna's mRNA-based flu vaccine after initially rejecting it. The agency reversed its earlier decision following discussions with the company, which proposed a revised approval plan. If authorized, the vaccine may be available for adults aged 50+ in the 2026-2027 flu season.

The U.S. Food and Drug Administration (FDA) has decided to review Moderna's new mRNA-based seasonal influenza vaccine following an earlier rejection, according to a company announcement on Wednesday. This decision reverses the agency's previous position regarding the vaccine application.

Background on Initial Rejection

About two weeks ago, the FDA issued a formal letter declining Moderna's submission for approval of its first mRNA flu shot. Such refusals are considered unusual for the federal agency. Moderna disclosed the content of the letter, which indicated that the refusal was based on the design of the company's clinical trial. Specifically, the control group used in the study did not align with the best-available standard of care in the United States at the time the trial was conducted. Moderna emphasized that the FDA's refusal did not reflect any concerns about the safety or efficacy of the vaccine itself.

Moderna's Response and Revised Regulatory Approach

Following the FDA's initial denial, Moderna engaged in discussions with the agency and proposed an adjusted regulatory strategy. The company outlined separate approval tracks according to age groups:

• Full approval for adults aged 50 to 64 years.
• Accelerated approval for adults aged 65 years and older, contingent on a post-marketing study for this population.

Moderna stated that, if authorized, the vaccine could become available for individuals aged 50 and above during the 2026–2027 influenza season.

Company Statement

Moderna's CEO, Stphane Bancel, noted the progress: “We appreciate the FDA’s engagement in a constructive Type A meeting and its agreement to advance our application for review. Pending FDA approval, we look forward to making our flu vaccine available later this year so that older adults in the U.S. have access to an additional option to protect themselves against influenza.”

Additional Context

Last week, Moderna highlighted that the FDA’s initial refusal was not consistent with earlier guidance provided by the agency. The revised regulatory plan is designed to address the FDA’s concerns regarding trial methodology while allowing for timely access to the vaccine for older adults, who are particularly vulnerable to seasonal influenza.

Sources:

• FDA to review Moderna's mRNA flu shot, reversing previous decision, company confirms
• FDA Reverses Stance on Moderna's mRNA Flu Shot
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