Topic overview
In brief
- The FDA approved Moderna's mRNA flu vaccine, mFlusiva, for adults aged 50 and older.
- Clinical trials showed mFlusiva to be 27% more effective than standard flu vaccines.
- This approval represents a significant advancement in flu vaccination options for older adults.
Summary
In August 2025, the U.S. Food and Drug Administration granted approval for Moderna's mRNA flu vaccine, known as mFlusiva, marking a significant milestone as the first influenza vaccine utilizing mRNA technology. This approval specifically targets adults aged 50 to 64 with traditional approval and adults aged 65 and older with accelerated approval, contingent upon further clinical trials to assess efficacy in the older demographic. The decision followed a late-stage trial involving over 40,000 participants, which demonstrated that mFlusiva was approximately 27% more effective than standard flu vaccines.
The approval process faced initial resistance, as the FDA had previously declined to review Moderna's application earlier in the year. However, after discussions with the company, the agency reversed its decision, allowing the vaccine to proceed to review. This change in stance was influenced by the promising results from clinical trials and the potential benefits of mRNA technology in addressing public health challenges. Health Secretary Robert F. Kennedy Jr. has been a vocal critic of mRNA vaccines, which added complexity to the approval process.