August 6, 2026
(SeaPRwire) - By: Ethan Gallagher On August 5, the U.S. Food and Drug Administration (FDA) made history by approving the first mRNA-based vaccine for influenza. This approval has been met with excitement from health experts, who believe the shot, made by Moderna, could offer several advantages over traditional flu vaccines. However, the timing of the approval is somewhat controversial, as federal health agencies have recently scaled back their recommendations for flu vaccines for many people. In a study published in May 2026 in the New England Journal of Medicine, Moderna's mRNA-based flu shot, called mFlusiva, was found to be up to 27% more effective in preventing flu than any of the four currently available flu shots. Among more than 40,000 people over age 50 who were randomly assigned to receive either mFlusiva or one of the four existing flu shots, those who received a single dose of the mRNA flu vaccine were on average 27% less likely to have lab-confirmed influenza-like illness than those getting another type of flu shot. Dr. Jeanne Marrazzo, CEO of the Infectious Diseases Society of America, called the approval "a historic event and incredibly exciting, both scientifically and from a public-health standpoint." Stéphane Bancel, Moderna's CEO, added that "Flu remains a significant public health challenge, and mFlusiva provides an important new option for America’s seniors." One of the key advantages of the mRNA-based flu vaccine is its ability to match influenza strains more effectively. Marrazzo explained that the better the match, the more effective the shot in preventing flu and some of its serious consequences, including pneumonia, respiratory distress, and even organ failure in those who are most vulnerable to infections, which include older people, young children, and those with weakened immune systems. Another advantage of the mRNA technology is its speed of development. Because the mRNA technology relies on a genetic plug-and-play model, in which different genetic sequences for any virus or pathogen can be switched into the vaccine, the shot takes around six weeks to develop. Current flu vaccines, on the other hand, take up to six months to create because they require growing the influenza virus in eggs before the virus is processed into the vaccine to activate the proper immune response. Currently, the World Health Organization (WHO) convenes a group of influenza experts each year to study the flu that circulates among populations in the southern hemisphere of the globe to determine which strains of the virus should be targeted in a vaccine for the northern hemisphere, where colder climates generally contribute to worse flu seasons. However, this analysis is not always accurate, and can lead to mismatches that produce weak vaccines. "We see this play out in [vaccine] efficacy that ranges anywhere from 50% to 60% in a good year to 20% in a not-so-good year," says Marrazzo. But with an mRNA-based flu shot, manufacturers won't need as much lead time to develop the vaccine, and could therefore better track and match influenza strains causing disease in real time. Moderna plans to have mFlusiva available in the fall as flu vaccine campaigns start, but only for a select group of people. The FDA approved the shot for people ages 50 and older, the group that recently-revised U.S. government guidelines say should be receiving flu shots every year. The current recommendations differ from previous guidelines, which advised that anyone six years and older, including pregnant women, should be vaccinated against both flu and COVID every year. While the CDC continues to make this recommendation on its website, in January, the Trump Administration revised this guidance for routine vaccination and instead shifted the decision to vaccinate to individual families and their physicians. Disagreeing with the change, many health organizations—including the American Academy of Pediatrics, the American Medical Association, and the American College of Obstetricians and Gynecologists—continue to recommend yearly flu shots for most people. The approval of the first mRNA flu vaccine is an important milestone for public health, says Marrazzo, but it's tempered by the current U.S. political environment that fuels skepticism about both the effectiveness and safety of vaccines in general, and about mRNA technology in particular. "We have never been technically at a more exciting time in terms of mRNA vaccines. There are all kinds of incredibly cool stuff happening," she says. "Yet in the public eye, we are taking five steps backward as trustworthy emissaries for the advancement of science, all due to the undermining of research and our credibility as trusted advisors." mFlusiva's road to approval exemplifies this now-fraught environment for vaccines in the U.S., after the FDA initially dropped it from review in February. The agency sent Moderna a "Refusal-to-File" letter, notifying the company that it would not review the vaccine and stating that the study did not provide a proper control arm against which to compare mFlusiva, and that using existing flu shots as comparators "does not reflect the best-available standard of care." In prior discussions before submitting its request for approval, the FDA suggested that the company provide data comparing mFlusiva among those 65 years or older to higher dose flu vaccines for this older population, which is at higher risk of complications from flu. Moderna says it provided the additional data. After receiving the Refusal-to-File letter, Moderna’s executives and scientists met with the FDA and agreed to seek full approval for people 50 to 64 years old, and accelerated approval for people 65 years or older, as well as conduct another study in the latter population. Under FDA’s accelerated approval, drugs can be approved sooner based on results of early benefit while further studies on longer term benefit are completed. Days after refusing to review the mRNA flu shot, the FDA decided to consider it for approval. Marrazzo says she can’t think of another drug that experienced such about-face decisions from the FDA. "It’s hard to read as anything other than a political decision from above," she says. "I don’t know for certain if that’s true, but that’s my supposition, if you trace back to Secretary [Robert F.] Kennedy’s overt hostility to mRNA vaccines. It’s a really good thing that there was a reconsideration and that science won out." Kennedy, who heads the Department of Health and Human Services that oversees the FDA, is a longtime skeptic of vaccines. In 2025, he halted 22 projects, worth $500 million, focused on developing mRNA vaccines for respiratory diseases, including for pandemic flu. Mixed signals from federal health authorities are contributing to confusion among the public, who are increasingly questioning the effectiveness and safety of vaccines, despite what scientists maintain is a strong track record of their benefit with relatively low risk. One of the reasons people are reluctant to get a flu shot is because of its sometimes weak effectiveness in protecting against symptoms. But an mRNA-based vaccine should improve on that since its shorter development time gives manufacturers a better chance of matching influenza strains in real time. "Will the public buy it? That’s another question entirely," says Marrazzo. The future of the mRNA flu vaccine remains uncertain. While the technology has the potential to revolutionize the way we approach flu vaccination, the current political climate and public skepticism could pose significant challenges. It will be important for health experts and policymakers to work together to communicate the benefits of the vaccine and address any concerns that the public may have. Only then can we hope to fully realize the potential of this breakthrough technology and protect ourselves and our communities from the threat of influenza. Author bio: Ethan Gallagher, a Silicon Valley Hardware Architect and Infrastructure Strategist
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