Moderna’s New mRNA Flu Shot Opens for Seniors Over 50

The first mRNA flu vaccine has arrived in the United States. Moderna’s product, called mFlusiva, uses the same messenger‑RNA platform that powered the Covid shots. It is the first flu shot in the country that follows this new technology. Health officials say the shot is only for people who are 50 years old or older. The Centers for Disease Control and Prevention urges everyone in that age group to get the jab by the end of October. At this point, the CDC has not yet begun to track flu cases for the season.

In a late‑stage study published in May, mFlusiva proved about 27 percent more effective than a standard flu shot. The Food and Drug Administration granted a regular approval for adults aged 50 to 64 and an accelerated clearance for those 65 and above. Moderna must run another trial for the older group as a condition of the approval. Pharmacies report that patients are confused about who can receive the shot, how it differs from traditional vaccines, and where to find it. An independent pharmacist in Ohio, Emlah Tubuo, said, "If you have not celebrated your 50th birthday, this vaccine should be of no interest to you."

The way the vaccine teaches the immune system is its biggest change. Most classic flu shots contain a dead virus that is often grown in eggs, while mFlusiva carries a tiny piece of genetic code. This mRNA acts like a temporary instruction sheet, telling the body how to spot the flu virus, and it is later broken down. The shot does not protect against Covid‑19; it targets only influenza. It is a trivalent formulation, covering two A strains and one B strain. Because the production line is faster, Moderna says the shot can be ready in two to three months, compared with the six months needed for egg‑based vaccines. Dr. William Schaffner, an infectious‑disease expert at Vanderbilt, highlighted this speed advantage.

The approval path was not smooth. Moderna’s early trial compared mFlusiva with a standard‑dose flu shot for seniors 65+, even though the CDC recommends a high‑dose version for that group. The FDA initially refused to review the application, then reversed its decision and required a post‑approval study. In June, an independent FDA advisory panel voted unanimously to endorse the vaccine for older adults. The process has set the stage for the shot to reach pharmacies just before the flu season begins.