Moderna’s mFlusiva has become the first mRNA influenza vaccine approved by the FDA for adults 50 and older, with traditional approval for ages 50–64 and accelerated approval for those 65+. The decision follows a complex review that included an earlier Refuse‑To‑File over comparator choice and a unanimous VRBPAC vote. Moderna must complete a postmarketing trial in older adults, and the vaccine still needs CDC/ACIP recommendation at the mid‑October meeting before it can be included in national immunisation programmes.
Moderna’s mFlusiva Becomes First mRNA Flu Vaccine Approved By FDA, Awaits CDC/ACIP Guidance
Moderna mRNA flu shot wins FDA approval but awaits CDC recommendations
Moderna has received U.S. Food and Drug Administration (FDA) authorization for its mRNA influenza vaccine, mFlusiva, marking the first mRNA-based flu shot licensed in the United States for use in adults aged 50 years and older. The approval is split between traditional approval for adults 50–64 and accelerated approval for those 65 and older, the latter requiring a post‑marketing study to confirm benefit in the older population.
Clinical Data and Regulatory Path
Approval for the 50–64 age group was supported by a Phase III trial that enrolled more than 40,000 participants and showed mFlusiva was superior to standard‑dose, licensed influenza vaccines at preventing influenza‑related illness. A separate Phase III study in adults ≥65 compared mFlusiva with a high‑dose comparator; because that authorization used the FDA’s accelerated pathway, Moderna must complete a confirmatory postmarketing clinical trial to verify clinical benefit in the older cohort.
Earlier in 2026 the FDA issued a rare Refuse‑To‑File (RTF) letter over concerns that the Phase III program had not used an optimal comparator. After meetings and an amended submission, the agency accepted the application and its Vaccines and Related Biological Products Advisory Committee (VRBPAC) later voted unanimously in June that the benefits of mFlusiva outweighed its risks.
Commercial And Political Context
Moderna’s shares rose modestly on the approval, climbing to $58 at market open on 6 August from a pre‑announcement close of $56.99. Analysts see commercial potential: William Blair projects peak sales of roughly $1.16 billion for mFlusiva.
Beyond commercial considerations, the vaccine faces political and reputational headwinds in the U.S. Health Secretary Robert F. Kennedy Jr. has publicly expressed skepticism about mRNA platforms and, under his leadership, the Department of Health and Human Services (HHS) cancelled about $500 million of federally funded mRNA contracts in August 2025. The Advisory Committee on Immunization Practices (ACIP), which advises the Centers for Disease Control and Prevention (CDC), has also been the focus of controversy after membership changes and a contentious December 2025 vote to withdraw newborn hepatitis B vaccine recommendations.
Next Steps
Although FDA authorization is now in hand, mFlusiva requires a recommendation from the CDC’s Advisory Committee on Immunization Practices before it can be adopted into national immunisation programmes. Moderna will seek ACIP consideration at the committee’s mid‑October meeting. If ACIP recommends the vaccine and CDC accepts that guidance, public‑health programmes will be able to include mFlusiva in seasonal flu campaigns for the authorized age groups.
Moderna’s clearance marks the company’s fourth FDA‑approved vaccine and highlights both the promise of mRNA technology—particularly its ability to update formulations quickly in response to new strains—and the regulatory, scientific and political challenges that accompany novel vaccine platforms.
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