FDA Clears First mRNA Flu Vaccine for Adults 50 and Older

The U.S. Food and Drug Administration has approved the nation’s first mRNA-based influenza vaccine for adults aged 50 and older, marking a major milestone for Moderna after months of regulatory uncertainty surrounding mRNA vaccines. The decision comes after the agency previously declined to review the shot, drawing criticism from scientists and medical experts amid broader efforts by the Robert F. Kennedy Jr.-led Department of Health and Human Services to reduce support for mRNA vaccine programs.

Moderna announced that its seasonal influenza vaccine, mFLUSIVA, has been authorized for use in adults aged 50 and above. The approval follows results from a Phase 3 clinical trial involving nearly 41,000 participants between the ages of 50 and 64, which showed the vaccine was approximately 26.6% more effective at preventing influenza infections than traditional flu vaccines.

In June, the FDA’s independent vaccine advisory committee unanimously backed approval of the vaccine for people aged 50 to 64. The agency also granted accelerated approval for adults aged 65 and older based on the panel’s recommendation. That authorization could become a full approval if future clinical trial results continue to demonstrate favorable outcomes.

Moderna said it plans to make mFLUSIVA available to eligible adults in the United States for the 2026–2027 flu season.

Commenting on the approval, Moderna CEO Stéphane Bancel said, “Flu remains a significant public health challenge, and mFLUSIVA provides an important new option for America’s seniors. This approval also reflects the ongoing potential of our mRNA platform.”

The approval marks a reversal from the FDA’s earlier position. In February, Moderna disclosed that the agency had refused to review its application after the FDA’s top vaccine regulator, Dr. Vinay Prasad, questioned the company’s choice of comparator vaccine in its clinical studies, arguing it was not the strongest available option. Prasad, a supporter of Robert F. Kennedy Jr. and a critic of COVID-19 vaccines, faced criticism over the decision. FDA Commissioner Marty Makary later described the initial refusal as “part of a conversation that occurs with all drug makers,” easing concerns that the application had been permanently rejected.

The decision also comes amid significant changes to federal vaccine policy. Last year, Kennedy announced the cancellation of nearly $500 million in contracts and grants supporting mRNA vaccine development through the Biomedical Advanced Research and Development Authority (BARDA). The Department of Health and Human Services said it was carrying out a “coordinated wind-down of its mRNA vaccine development activities” under BARDA. Kennedy argued that data indicated the 22 mRNA vaccine projects funded by BARDA “fail to protect effectively against upper respiratory infections like COVID and flu,” and said future investments would focus on “safer, broader vaccine platforms that remain effective even as viruses mutate,” without providing additional details.

Rick Bright, an immunologist and former BARDA director, criticized the funding cuts, stating, “BARDA invested in mRNA technology precisely because it could deliver safe, scalable vaccines in record time, a capability proven during COVID. By dismantling that platform, we’re crippling our front-line defense, just ahead of unknown biological threats.”