The Food and Drug Administration this week approved the first mRNA flu vaccine for adults 50 and older.
Health experts lauded the decision, calling it a victory as vaccine skepticism seems to be on the rise among Americans.
Moderna said it hopes to begin rolling out its mFlusiva jab for this year’s flu season, though doctors predicted the “loss of faith” in public health may limit its initial popularity.
Here are five things to know about the new vaccine and its approval:
mRNA vaccines work differently
Most commonly associated with covid-19 vaccines, mRNA shots work by giving the body genetic instructions to produce a protein capable of eliciting antibodies to fight a virus, said Dr. Amesh Adalja, a Pittsburgh-based infectious disease specialist and senior scholar at the Johns Hopkins Center for Health Security.
Traditional vaccines, however, often include a weakened form of a virus, allowing the body’s immune system to learn how to respond in the case of a real infection.
Pfizer and Moderna’s covid-19 vaccines used mRNA technology, and Moderna also later produced an mRNA vaccine for respiratory syncytial virus, or RSV.
The company’s mFlusiva vaccine is the first mRNA vaccine approved to fight the flu, which kills tens of thousands of Americans each year.
In 2023, scientists Katalin Karikó and Drew Weissman were awarded the Nobel Prize in physiology or medicine for their mRNA research that ultimately led to the development of the covid-19 vaccines.
mRNA vaccines can be created faster
Because medical experts don’t have to spend time growing a virus, they can develop and deploy mRNA vaccines much more quickly.
Plus, doctors can pivot later in the year if a dominant flu strain emerges that is different from the one predicted to be most prevalent, Adalja said.
Ultimately, he said, the approval of the mRNA vaccine could cut the roughly six-month lead time for traditional flu vaccines in half.
That’s a significant advancement, said Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor University and a prominent national vaccine advocate.
But it remains an open question whether mRNA vaccines ultimately could displace traditional flu jabs, he said.
Pharmacies’ plans vary
Though Moderna said it’s hoping to roll out its mFlusiva vaccine for this flu season, two major pharmacies told TribLive they don’t plan to offer it.
Giant Eagle spokeswoman Jannah Drexler said in a statement the grocery chain — recently acquired by Kroger, pending regulatory approval — would not offer the new shot.
“If we see a strong demand for mFlusiva from our patients, we will consider adding it to our available offerings,” Drexler’s statement said.
It’s a similar story from CVS.
The nation’s largest pharmacy chain already has “ample supply” for the 2026-27 flu season, including “traditional and senior dose,” according to Roslyn Guarino, a CVS spokeswoman.
“We’ll continue to evaluate Moderna’s new vaccine, as we do with all our offerings, to ensure we continue to meet the needs of the communities we serve,” Guarino’s statement said.
Neither company offered a reason why they do not plan to offer the new vaccine, but Drexler said Giant Eagle typically finalizes its vaccine plans earlier in the year.
Wilson’s Pharmacy, a family-owned drugstore in Pittsburgh’s Lawrenceville neighborhood, will have mFlusiva.
Pharmacy technician Elizabeth Quinn told TribLive on Friday that Wilson’s likely will have the mRNA vaccine in stock in September.
RFK Jr. has been opponent
Health and Human Services Secretary Robert F. Kennedy Jr., a vaccine skeptic, has spoken out against mRNA technologies in the past.
Last August, he canceled $500 million in mRNA vaccine research, saying in part, “mRNA technology poses more risks than benefits for these respiratory viruses.”
It’s a position most medical experts pan, including Dr. Paul Offit, director of the Vaccine Education Center and a physician at Children’s Hospital of Philadelphia.
“It’s a cruel joke being played on the American people,” Offit said. “Ignore him.”
Earlier this year, the FDA declined to review mFlusiva in a supposed dispute over testing methodology. But the agency quickly did an about-face after receiving pushback when Moderna made the decision public, according to reporting by The New York Times.
In June, an independent advisory committee unanimously recommended the FDA approve the vaccine, saying its benefits appeared to outweigh any risks, the Associated Press reported.
In a statement to TribLive, the FDA said its approach has been “consistent,” saying the agency “evaluates each application on its own merits using established scientific and regulatory standards.”
“Approval decisions are based on the totality of the scientific evidence, including clinical, immunogenicity, safety and manufacturing data. The FDA cannot comment on specific products that may be under review,” the agency’s statement said.
Vaccine skepticism heightened
Almost half of American adults surveyed by Politico in March said they think the science on vaccines remains up for debate and that it’s damaging to require people to receive them.
Offit and Hotez said they expect that to persist, partially because of Kennedy.
“There’s an erosion of faith in public health; there’s an erosion of faith in vaccines,” Offit said.
Still, the approval is a step in the right direction, Hotez said.
“It’s a good sign,” Hotez said. “It means the agencies are still moving forward.”