FDA Panel Considers a First-Of-Its-Kind Flu Vaccine Using mRNA Technology

A group of health experts met in Washington on Thursday to discuss a brand-new kind of flu vaccine. The shot is made by the company Moderna and uses mRNA technology — the same science that helped create COVID-19 vaccines. Moderna wants the Food and Drug Administration, known as the FDA, to approve the vaccine for people age 50 and older. This could be a big step in how the United States fights the flu each year.

Every year, tens of thousands of Americans die from the flu. Older adults face the greatest risk of getting very sick. Several flu vaccines already exist in the U.S., and three of them are made specifically for people 65 and older. But Moderna's new shot, called mFlusiva, works differently from those older vaccines.

mRNA technology teaches the body how to fight a virus without using a live or weakened version of it. This method won the Nobel Prize in science, and it was used to make the COVID-19 vaccines that many people received during the pandemic. One big advantage of mRNA vaccines is that they can be made much faster than traditional vaccines. That speed could be important if the flu virus changes suddenly and new doses are needed quickly.

In a large study of 40,000 people age 50 and older, Moderna's vaccine lowered flu cases by about 27% compared to people who got a different flu vaccine brand. Before the expert panel met, the FDA published a review of that data and said it looked positive with no safety concerns. The panel of advisers will look closely at this information to help the FDA make its final decision.

Moderna is asking for full approval of mFlusiva for people ages 50 to 64. For people 65 and older, the company is asking for temporary authorization while it does more testing. The FDA also reviewed a smaller study that showed the mRNA shot produced flu-fighting antibodies at a level similar to a high-dose vaccine made for older adults.

Earlier this year, the approval process hit a bump. A top FDA official at the time, Dr. Vinay Prasad, blocked Moderna's application. He said the company should have tested its vaccine against a stronger, high-dose flu shot meant for seniors, not a standard one. This was seen as a sign that the FDA was reviewing vaccines more strictly under Health Secretary Robert F. Kennedy Jr.

Moderna pushed back against that decision. The company pointed out that FDA staff had already agreed to the study's design, and it shared results from a second, smaller study that compared its shot to the high-dose senior vaccine. Just a few days after that disagreement, the FDA agreed to accept Moderna's application and move forward. The expert panel's recommendation will help the FDA decide whether mFlusiva should be approved before the winter flu season begins.