There’s a new name on the flu shot menu, and it’s made with mRNA. Flu season is here, and for the first time in America, one of the shots uses that technology. The FDA approved Moderna’s flu vaccine, mFLUSIVA, for adults 50 and older back on Aug. 5. We’re now about ten weeks past the headlines, so here is what the approval means this fall.
What the mRNA flu vaccine approval actually covers
The shot is also known as mRNA-1010. It is Moderna’s fourth FDA-approved product, and the company’s release calls it the first mRNA-based flu vaccine. Moderna’s CEO, Stéphane Bancel, said it “provides an important new option for America’s seniors.” It also follows the company’s recent momentum in mRNA cancer research.
The approval comes in two parts, and they are not equal. For ages 50 to 64, it is a traditional approval built on a Phase 3 trial of 40,805 adults in 11 countries, according to Becker’s Hospital Review. For ages 65 and older, it is an accelerated approval. Moderna must now run a follow-up study against a high-dose flu vaccine to keep that indication.
How well does the Moderna flu vaccine work?
In the trial, the shot showed 26.6% relative efficacy versus a standard-dose flu vaccine. In plain English, it prevented more flu cases than the regular shot did. It did not beat nothing by 27%, and that distinction matters.
Side effects were more common than with the standard vaccine, though mostly mild and gone within two days. Injection-site pain hit 65.8% of participants, fatigue 45.1% and headache 37.8%, Pharmacy Times reported. So yes, your arm may complain for a day or two.
Here’s the thing for people 65 and up
Seniors are the group that needs flu protection most. Adults 65 and older made up 57% of flu hospitalizations and 71% of deaths in the 2024-25 season. Right now, a high-dose vaccine is the recommended option for that age group.
However, Moderna’s data for seniors came from immune-response comparisons, not proof of fewer illnesses. The company says it will gather head-to-head data against the high-dose shot this winter, ABC News reported. If you are 65 or older, ask your doctor which shot fits you before assuming this mRNA flu vaccine is better.
Why the mRNA influenza vaccine almost never happened
This approval had a rocky road. In February, the FDA issued a refusal-to-file letter, which Moderna disclosed to the SEC. The dispute reportedly centered on the comparison vaccine used in the trial, not on safety.
A week later, the FDA agreed to review it. (That’s a fast turnaround by paperwork standards.) An FDA advisory panel then voted 9-0 in June in its favor.
The approval also came despite repeated criticism of mRNA technology from HHS Secretary Robert F. Kennedy Jr., who last year canceled 22 mRNA vaccine projects, CBS News noted. Vaccine makers are racing on other fronts too, as the global push for Ebola vaccines shows.
So can you get one right now?
That is the honest open question. Moderna said supply would reach select U.S. retailers “in the coming weeks” for the 2026-27 season. We could not confirm that shots are on shelves today, and we found no pricing or CDC recommendation yet. Call your pharmacy or doctor before you plan around it.
The standard flu shots you already know remain available. Moderna’s version also faces review in the EU, Canada and Australia. For now, the first mRNA flu shot is approved, and the real test is whether you can actually roll up a sleeve for it.
