Adults 50 and older can now ask for the nation's first mRNA flu vaccine at Walgreens and CVS pharmacies, though local stock varies by location.

The U.S. Food and Drug Administration approved the vaccine, called mFLUSIVA, on Aug. 5 for adults 50 and older, WLWT reported. Moderna, the vaccine's maker, said mFLUSIVA is available at more than 13,000 locations nationwide. Both Walgreens and CVS said they are stocking the shot in limited quantities, and availability varies by store. West Chester and Liberty Township residents can check nearby stock using Moderna's vaccine finder by entering a zip code.

During the 2024-25 flu season, adults older than 50 accounted for nearly 77% of flu hospitalizations, according to CDC data cited by WLWT, despite making up about a third of symptomatic cases. Adults older than 65 accounted for more than 70% of flu deaths while representing fewer than 9% of illnesses.

A Moderna clinical trial enrolling more than 40,000 adults 50 and older found mFLUSIVA was about 27% more effective against symptomatic illness than a standard flu shot. The FDA's independent vaccine advisory panel voted unanimously in June that the vaccine's benefits outweigh its risks.

Two types of approval

The FDA granted standard approval for adults 50 to 64. For those 65 and older, the agency granted accelerated approval, requiring Moderna to conduct a post-marketing study comparing mFLUSIVA against a high-dose flu vaccine. That study was required to begin by Aug. 31, with an interim report due Dec. 31, 2027.

Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center, called the accelerated approval "entirely appropriate," noting Moderna's obligation to come back to the FDA with further data on effectiveness and safety.

One wrinkle: the CDC has not added mFLUSIVA to its recommended flu vaccine list for fall 2026. The agency posted that it is maintaining last year's endorsements due to "legal uncertainties and inquiries," as Click2Houston reported. The CDC's Advisory Committee on Immunization Practices (ACIP) has not met since a federal judge ruled in March that HHS Secretary Robert F. Kennedy Jr. did not follow federal procedures when replacing the committee's members. A meeting is scheduled for October.

Leading medical societies, including the Infectious Diseases Society of America and the American Academy of Family Physicians, are recommending mFLUSIVA as an option for adults 50 and older.

Dr. Ronald G. Nahass, president of the Infectious Diseases Society of America, told WLWT the priority is simple: "Get a flu shot. Whatever is available."

Side effects and who should skip it

The mRNA vaccine showed higher rates of side effects than a standard-dose shot. Most reactions, including injection-site pain, muscle aches, headache, fever and chills, were mild to moderate and resolved within days. Serious adverse events occurred at similar low rates in both groups.

People allergic to any of the vaccine's ingredients or who have had Guillain-Barré syndrome after a past flu shot should not get mFLUSIVA.

How to find it

Because most pharmacies ordered their flu vaccine supply earlier in the year, mFLUSIVA stock may be limited this season. Dr. Michelle Fiscus, chief medical officer for the Association of Immunization Managers, said the vaccine may be easier to find at larger pharmacy chains.

Moderna said mFLUSIVA should be covered by most commercial insurance plans and Medicare Part B. The National Association of Insurance Commissioners said consumers should check with their health insurer to confirm coverage.

Doctors recommend getting a flu shot before the end of October. It takes about two weeks for the vaccine to build the body's defenses after the shot.