The FDA approved the trivalent flu vaccine mRNA-1010 (mFLUSIVA) for use in all adults age 50 years or older, Moderna announced on Wednesday. It is the first approved flu vaccine to use the mRNA technology that sped COVID-19 vaccine development.
Moderna received traditional approval in adults ages 50 to 64 years; accelerated approval was granted for those 65 and older, with a postmarketing effectiveness study planned for that population.
Approval in the younger group was based on the pivotal phase III Fluent randomized trial, in which the mRNA vaccine — which targeted influenza A/H1N1, A/H3N2, and B/Victoria — outperformed standard-dose flu shots, with a relative vaccine efficacy of 26.6% among all participants 50 and up. Among more than 19,000 adults ages 65 and older in the Fluent trial, the relative vaccine efficacy of mRNA-1010 was 27.4%. Most adverse reactions were mild to moderate and transient. Serious adverse event rates were 2.2% in mRNA-1010 recipients versus 1.9% in the standard-dose group.
Approval in the older group was based on a separate phase III study that showed mRNA-1010 led to greater immunogenicity compared with a high-dose comparator flu vaccine in those 65 or older.
The FDA’s decision “demonstrates the continued strength and versatility of our mRNA platform,” said Stéphane Bancel, Moderna’s CEO, in the statement. “This approval also reflects the ongoing potential of our mRNA platform to help address important public health challenges through continued scientific innovation.”
Ronald Nahass, MD, president of the Infectious Diseases Society of America, said in a statement that the approval “is welcome news” that “highlights the tremendous potential of mRNA vaccine technology.”
“Unlike conventional manufacturing, the mRNA platform allows for streamlined development and rapid responses to emerging mutations in viruses,” Nahass noted. “Demonstrating the success of mRNA for influenza opens the door to broader applications, accelerating our ability to create safe and targeted vaccines for a wider range of preventable diseases.”
The mRNA vaccine’s approval was nearly derailed under the leadership of HHS Secretary Robert F. Kennedy Jr., a prominent anti-vaccine activist before joining the federal government. Moderna’s vaccine uses the mRNA platform the company used to develop COVID shots.
In February, the FDA initially rejected Moderna’s application, with then-vaccine chief Vinay Prasad, MD, MPH, asserting the company lacked an “adequate and well-controlled trial” as it failed to compare the mRNA vaccine to “the best-available standard of care in the United States at the time of the study.” The agency reversed itself after the drugmaker showed immune response data in the older subset at least matched the high-dose vaccines and committed to a postmarketing comparative effectiveness study.
In a June meeting, the FDA’s Vaccines and Related Biological Products Advisory Committee unanimously endorsed mRNA-1010 and said the benefits of the mRNA vaccine outweighed its risks for preventing the flu in adults 50 to 64 years and in those 65 and up.
Moderna said the mRNA flu vaccine should be available in the U.S. for the upcoming 2026-2027 flu season.
