Federal vaccine policy has been under unusual scrutiny in 2026 as the Trump administration’s health leadership has revisited long-settled debates over vaccine safety and regulation. That debate sharpened this week when the Food and Drug Administration approved Moderna’s first mRNA flu shot, despite Health and Human Services Secretary Robert F. Kennedy Jr.’s past statements describing COVID-19 shots as “the deadliest vaccine ever made,” according to FactCheck.org’s review of his Senate testimony and prior remarks.
FDA approves Moderna’s flu shot after a contentious review
The FDA approved Moderna’s seasonal influenza vaccine, branded mFlusiva, on August 5, making it the first influenza vaccine cleared in the United States that uses messenger RNA technology, according to FDA briefing materials and contemporaneous reporting from Reuters and other national outlets. The approval followed a biologics license application that FDA records show was received on December 5, 2025, and formally filed on February 17, 2026. Moderna’s late-stage studies enrolled more than 43,000 adults age 50 and older, according to company disclosures and reporting cited during the regulatory review.
The decision came after an unusually public dispute between Moderna and FDA earlier this year. In February, Moderna said the agency had issued a refusal-to-file letter for mRNA-1010, arguing that the company relied on a standard-dose comparator rather than a flu shot preferentially recommended for older adults. The FDA later reversed course and accepted the application for review, setting an August 5 action date, according to Reuters and FDA advisory committee records.
In June, FDA vaccine advisers voted 9-0 in favor of the shot’s benefit-risk profile for adults ages 50 to 64 and 9-0 again for adults 65 and older, according to Moderna and the FDA’s Vaccines and Related Biological Products Advisory Committee documents. That unanimous vote helped clear the final stage before licensure.
For patients and pharmacies, the immediate significance is national rather than state-specific. The approval adds a new platform to a crowded U.S. flu vaccine market that already includes egg-based, cell-based, recombinant and nasal-spray products, according to FDA vaccine listings. What is confirmed is that mFlusiva is now licensed; what is not yet clear is how broadly it will be stocked in individual states, counties or local pharmacy chains during the 2026-27 flu season.
Neither the FDA materials surfaced in public records nor Moderna’s earlier regulatory statements provided a location-by-location rollout plan. The company had previously said it expected the vaccine could be available for the 2026-27 season if approved, but it has not publicly released a comprehensive list of distribution sites. That means residents may see availability vary by provider, insurer contracts and pharmacy purchasing decisions in the early weeks of the fall vaccination campaign.
The approval also stands out because it happened under an HHS secretary who has been sharply critical of mRNA products. During his confirmation process, Kennedy defended prior statements that the COVID-19 vaccine was the “deadliest vaccine ever made,” a claim FactCheck.org said was false and rooted in a misuse of adverse-event reports. Even so, the FDA moved ahead with a full biologics approval for another mRNA vaccine product.
The approval underscores the divide between Kennedy’s rhetoric and the actions of the agencies he oversees. Reuters reported earlier this year that Kennedy, a longtime critic of mRNA technology, also oversaw the cancellation of a large government contract tied to mRNA vaccine development for bird flu and other threats. At the same time, FDA staff continued processing Moderna’s flu application through the standard review pathway, including a public advisory committee meeting and a final action by the agency.
Moderna has argued that mRNA technology can speed vaccine development and improve strain matching as respiratory viruses evolve. In Phase 3 data the company announced in January, mRNA-1010 showed relative vaccine efficacy of 26.6% over a standard approved flu shot in adults 50 and older. FDA briefing documents for the June advisory meeting said approval would provide a new option for seasonal influenza prevention if regulators determined the benefits outweighed the risks.
For residents deciding what to expect this fall, the practical answer is that another FDA-approved flu shot option is entering the market, but access details will depend on provider inventory and coverage rules that have not yet been fully published. The broader policy fight over mRNA vaccines is still active in Washington, but as of August 5, the federal government’s own drug regulator had formally added an mRNA flu vaccine to the U.S. arsenal ahead of the next flu season.