Flu season is approaching, and a new vaccine has been released to help fight the virus this year.
About mFlusiva
mFlusiva is an mRNA vaccine created by Moderna. The U.S. Food and Drug Administration approved it for adults 50 and older in August 2026.
mRNA, or messenger ribonucleic acid, is a molecule that brings genetic instructions from DNA to the parts of the cell that build proteins.
mRNA vaccines teach cells how to make a viral protein called an antigen, which the body identifies as a threat. The immune system creates antibodies in response, targeting the antigen and creating a means for the body to fight illness.
It’s the same virus-fighting technology used in the COVID-19 vaccine and takes less time to produce than other flu shots, according to Dr. Jonathan Pinsky, medical director for infection prevention at Endeavor Health Edward Hospital.
“They are the mRNA that encodes the same protein that’s in the vaccine. But those can be produced rapidly in a matter of weeks or maybe a few months. The advantage of that is, you have less lead time to develop a vaccine,” Pinsky said.
He said this allows mFlusiva to more effectively keep up with flu strains, should they change over time.
“So one of the big problems is when you’ve developed vaccines six months before (flu season), the virus could change. And by the time the vaccine comes out, you may not be a good match with the mRNA vaccine. (Now) you have a shorter lead time. You can rapidly produce (an mRNA vaccine),” Pinsky said.
How well does it work?
Trials involving thousands of adults showed the new vaccine had higher efficacy than others on the market.
“When they did the studies on this, there were 40,000 individuals above the age of 50 who received the mRNA vaccine,” Pinsky said. “And they found that it actually worked better in terms of preventing flu. And so they tested this during last year’s flu season, and it was about 25% better in terms of preventing illness with influenza. So it may actually be a better vaccine in the long run.”
Possible side effects
Side effects may include pain, tenderness and swelling at the injection site, along with fatigue, muscle pain, chills, nausea, vomiting and fever, according to Moderna.
Where can I get it?
mFlusiva is available at many pharmacies around the country, including Walgreens, CVS, Jewel Osco and Costco in Naperville, according to the Moderna website. Pinsky said stock may vary based on location.
“I suspect the reason for that is the supply,” he said. “This vaccine is newer, and I don’t know if pharmacies are going to be certain whether they have a supply of that.”
He recommends that everyone get vaccinated, regardless, as flu rates tend to increase during the fall and winter months each year.
“The important thing is to just get vaccinated for the flu. You know, not just really choose which one you want. I’d hate for someone to be kind of waiting for that mRNA vaccine, and not just maybe just get the traditional flu shot or the high dose flu shot if it’s available,” Pinsky said.
The CDC recommends influenza vaccination for anyone 6 months and older.
If you have a story idea, we want to hear from you!
