FDA approves first mRNA flu vaccine for adults 50 and older
The FDA approved Moderna’s first mRNA flu vaccine, offering stronger protection for adults age 50 and older.
The U.S. Food and Drug Administration has approved a new flu vaccine, Moderna’s mFlusiva, marking the public release of the first non-COVID-related mRNA vaccine in the U.S.
Moderna’s vaccine was approved for people aged 50 and older on the condition that it will run additional studies on its effectiveness in adults over 65. Existing trials involving more than 40,000 adults aged 50 and older found that Moderna’s mRNA was 26.6% more effective than the traditional flu shot.
“Flu remains a significant public health challenge, and mFLUSIVA provides an important new option for America’s seniors,” Moderna said in a statement.
While the technology behind mRNA vaccines has been in development for decades, it came to the forefront during the COVID-19 pandemic, when drug companies Pfizer and Moderna rolled out the first shots to fight the respiratory virus.
Though mRNA science has shown promise in treating or preventing disease beyond COVID, known vaccine skeptic and Secretary of the Department of Health and Human Services Robert F. Kennedy Jr. has rallied against its development, canceling roughly $500 million in related projects in 2025. Earlier this year, the FDA, which operates under HHS, declined to review the mRNA flu shot before changing course about two weeks later.
What is an mRNA vaccine and how is it different from other shots?
An mRNA vaccine, or messenger ribonucleic acid vaccine, is a type of immunization that uses a copy of a molecule called messenger RNA to help the body create an effective immune response. mRNA molecules already exist in the cells in your body and work to communicate information between your DNA and cells, according to the Cleveland Clinic.
Unlike traditional vaccines, which often use weakened, killed or partial viruses to trigger immunity, mRNA vaccines work by delivering genetic instructions that teach the body to make a harmless viral protein and mount an immune response, according to the Cleveland Clinic and the National Institutes of Health.
Think of a traditional vaccine as showing your immune system a sample of the virus. An mRNA vaccine instead gives your body the recipe to make a harmless sample on its own, so the immune system can practice recognizing it. It’s like getting a play-by-play of the other team’s moves and how to defeat them before the game even starts.
Once cells finish making the necessary proteins, they quickly break down the mRNA, which leaves the body after a few days. mRNA from vaccines does not alter DNA, notes NIH.
How mRNA vaccines work
mRNA vaccines were in development long before COVID
Before the new flu approval, the COVID-19 vaccines Comirnaty (Pfizer) and Spikevax (Moderna) were the only mRNA vaccines available to the public. Skeptics of the COVID shots at the time noted concerns about how quickly it was released. However, development of mRNA technology has spanned decades, and new studies have shown its promise in the treatment of other diseases, like cancer.
Though medical groups and experts have said there is no widespread evidence that COVID-19 vaccines are unsafe, the Trump administration has pushed for a COVID-19 vaccine injury list.
The side effects of the COVID-19 vaccine are generally on par with other vaccines, including tenderness at the injection site and a small chance of allergic reaction. In rare cases, mRNA COVID vaccines have been associated with an increased risk of myocarditis and pericarditis, the CDC says.
Who is the new flu shot approved for?
mFlusiva was given a traditional approval for adults aged 50 to 64, meaning it has already shown ample evidence that it provides the clinical benefit it claims to.
The shot was given an accelerated approval for those 65 years and older, meaning it was conditionally approved to get to people who need it faster, but the manufacturer must still conduct additional studies to confirm its benefits.
This means people 50 and older will be eligible for the shot when it’s released.
When can you get the new flu shot?
“Looking ahead, we expect mFLUSIVA to be available in the United States for eligible adults during the 2026–2027 respiratory virus season,” (November to April, peaking around January), Moderna said in a statement. “Beyond the U.S., regulatory submissions are under review in the European Union, Canada and Australia, with additional submissions planned later this year.”
Changes to flu vaccine under the Trump administration
The Centers for Disease Control and Prevention issued a memo in January removing universal recommendations for childhood vaccines that protect against flu and a handful of other diseases, including meningococcal disease, COVID-19 and hepatitis A and B. Instead, it said these vaccines are subject to “shared decision-making,” a process during which parents consult with health care providers on whether to administer the shots.
A federal judge blocked some of these changes in March, specifically those concerning COVID-19 and Hep B immunizations. HHS has vowed to appeal the decision. Former FDA Commissioner Marty Makary and former vaccine chief Vinay Prasad were also forced to resign earlier this year amid controversies over vaccine and rare-disease drug reviews, including Moderna’s flu vaccine application.
In the meantime, the official CDC webpage for the flu, last updated in September 2025, still recommends the flu vaccine for “everyone 6 months and older in the United States, with rare exception.”
The most effective way to prevent serious illness from the flu is vaccination, according to the World Health Organization, CDC and other leading medical institutions. Currently, the CDC especially recommends the vaccine for people at higher risk, which includes those over the age of 65, children younger than two, pregnant people and people with underlying health issues ranging from asthma to obesity.
The CDC generally recommends the vaccines be given from September to November, before cold and flu season kicks off, “ideally by October.”
Contributing: Reuters