The US Food and Drug Administration has approved the first mRNA vaccine for influenza, opening a new chapter for a technology that proved itself during the COVID-19 pandemic. The decision gives Americans a new option ahead of the fall flu season.
How it differs from old flu shots
Traditional flu vaccines are grown in eggs or cells, a process that takes months. mRNA vaccines skip that step. They carry instructions that teach the body's own cells to build a harmless piece of the virus, which trains the immune system to fight the real thing.
Because mRNA vaccines are faster to produce, manufacturers can update them closer to flu season. That could fix a long-standing weakness of flu shots: by the time egg-based vaccines are ready, the circulating strains may have drifted.
What the trials showed
In clinical trials, the vaccine produced strong immune responses against multiple flu strains, including H1N1 and H3N2. Side effects were similar to those of existing flu vaccines, mainly sore arms, fatigue, and mild fever for a day or two.
Experts said the data is good enough to justify approval but noted that real-world effectiveness will take a few seasons to measure. Flu viruses mutate quickly, so no vaccine is a perfect match every year.
A bigger moment for mRNA
The approval is a milestone for mRNA technology, which is now being tested against RSV, shingles, and cancer. Researchers say the platform's speed and flexibility make it a powerful tool for responding to new threats.
Public health officials hope the new vaccine will lift vaccination rates and reduce the heavy toll of flu, which kills tens of thousands of Americans each year. For patients, the biggest change may be simple: a flu shot that is easier to update, faster to make, and just as safe as the ones they already know.