The Food and Drug Administration's top vaccine advisory committee voted unanimously today to recommend Moderna's mRNA influenza vaccine, mFlusiva, for adults 50 and over. This was its first time reviewing a new vaccine application since 2023.
The vote by the Vaccines and Related Biological Products Advisory Committee, or VRBPAC, is a step towards what may be the first vaccine filed and approved under the second Trump administration despite sustained criticism of vaccines from President Trump and Health and Human Services Secretary Robert F. Kennedy Jr. Indeed, last year, Kennedy pulled back almost $500 million in contracts to develop mRNA vaccines.
"It's such a breath of fresh air, considering what we've gone through with Robert F. Kennedy Jr." says Dr. Paul Offit, director of the Vaccine Education Center at the Children's Hospital of Philadelphia and former committee member of the FDA panel that voted Thursday.
The rocky road to the review
In February, the FDA declined to review Moderna's application for the mRNA flu vaccine but then reversed its decision two weeks later after criticism.
Messenger-RNA, or mRNA, provides instructions for the body to produce flu antigens to develop immunity. Moderna's mRNA flu vaccine includes microscopic doses of mRNA for three to four strains of the flu — totaling about the same weight that a fingerprint leaves on a mirror.
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Researchers used the technology to develop the COVID-19 vaccine – another reason why Kennedy has been critical of its use during the pandemic with vaccine mandates.
In addition to the flu vaccine providing potentially stronger protection, many public health and infectious disease experts are excited about the shot because mRNA vaccines can be produced much more reliably and quickly — and potentially faster than traditional flu vaccines. That could make the mRNA vaccine far more effective when a new flu strain suddenly emerges.
While some public concerns have persisted, Moderna and the FDA did not find credible safety risks in Thursday's review. Moderna wrote in its brief that the vaccine "does not enter the cellular nucleus, does not interact with the genome … and does not persist in the body."
The research
Results from Moderna's phase 3 trial were also published in the New England Journal of Medicine and Nature Immunology. Hanover Matz, postdoctoral researcher at Washington University in St. Louis, and colleagues examined the vaccine response from 75 patients in the trial in detail — looking at not only how many antibodies patients produced, but how good the antibodies were and why that might be the case.
"It's not something that is typically evaluated when anybody looks at vaccine research, whether it's a company or in academic research," Matz says. They found that the mRNA vaccine produced a longer-lasting response and antibodies that recognized more flu strains — which Matz says could explain why the mRNA vaccine may be better than today's flu vaccines.
"There were no shortcuts taken. There was a full efficacy evaluation done per standard FDA guidance … phase 3 efficacy studies conducted in tens of thousands of individuals," Dr. Anna Durbin, director of the Center for Immunization Research at Johns Hopkins University and VRBPAC member, said to NPR.
Dr. Jesse Goodman, former director of FDA's Center for Biologics Evaluation and Research, acknowledges that the mRNA vaccines became politicized and that there has been a tremendous amount of false information about them — like that they cause cancer or that they get into your cells' DNA. He says "these things are not possible [and] disproven."
Durbin points to the figure that over 6 billion doses of mRNA vaccines have been administered since 2020 and says they have an "incredibly safe safety profile" and "there is not a risk of DNA integration."
"The mRNA platform has really been a game changer for vaccines, and it's an incredibly important advancement in medical science," Durbin says. "We have to do a much, much better job in educating the public around that, but I have the highest confidence in the vaccine."
Goodman agrees. "It's not going to change overnight. And I'm sure there are people who are going to remain concerned about [m]RNA-based vaccines, and there will be people who spread erroneous information about it," he notes. "However, people will also look at the evidence."
The review
In the meeting, Dr. Lisa Grohskopf from the CDC presented that there have been at least 32 million flu cases, 390,000 hospitalizations and 24,000 deaths in the U.S. in the past 2025-2026 flu season. She said, "approximately 85% of those eligible for vaccination were not fully vaccinated against influenza."
Dr. Evan Anderson, vice president of epidemiology at Moderna, acknowledged flu prevalence and highlighted the issue of strain mismatch with current vaccines. Anderson said the proposed mRNA vaccine could shorten the window of time it takes to get a vaccine that targets a specific strain of flu from about 6 months now to 2-3 months — as used for COVID-19 vaccines — potentially improving the strain-selection accuracy and vaccine efficacy.
Dr. Gauri Raval, medical officer of the FDA's Division of Clinical and Toxicology Review, presented that "[the Moderna mRNA flu vaccine] may offer greater efficacy than the standard dose comparator in preventing more severe influenza-associated illness[es]." The FDA found no "major safety issues or deficiencies."
After six and a half hours, the committee voted. All nine members recommended the vaccine.
Durbin commended the FDA, Moderna and the rest of the committee — calling the meeting excellent and discussions robust. She says the public should be very confident in the vote.
What this means for the future of the FDA
The FDA's reversal on reviewing the vaccine was unusual, Offit says. "You can't say, yes, go ahead, spend tens of millions of dollars, and then, when they present data, say, no, we're not even going to look at this data. You can't do that." Dr. Vinay Prasad, who made the initial call and has since left FDA, "ultimately backed down," Offit says.
The FDA did not provide NPR a comment by the time of publication.
Offit says he was relieved to see the VRBPAC was left mostly intact in contrast to the CDC's gutted Advisory Committee on Immunization Practices, or ACIP. "It's great. It's just what you want. You want to have a lively, open discussion, a discussion that's open to the public."
Goodman concurs: "I'm encouraged that this is happening, and in what appears to be a balanced way that's paying attention to the feedback of the FDA vaccine experts and also the outside experts who really wanted to see this vaccine come forward and get reviewed in the light of day."
In the public hearing portion of the meeting, Michael Abrams, a senior researcher with non-profit organization Public Citizen, echoed those sentiments. "We urge the FDA to frequently convene this committee as well as many other expert advisory committees the agency, since January 2025, has insufficiently utilized."
There have been 44 vaccines approved between 2000 and 2019. Of those 44, the VRBPAC convened for 21 of them — meeting about once a year to review a new vaccine application.
Yet the VRBPAC hasn't convened for over three years for a new vaccine application. The most recent was May 18, 2023, for Pfizer's Respiratory Syncytial Virus vaccine.
Durbin agrees the VRBPAC has had fewer meetings since January 2025. A flu meeting normally held every spring did not happen in 2025, Durbin says as an example.
Durbin is more concerned about the other vaccine committee, CDC's ACIP, however. She explains, "ACIP has a different purpose than VRBPAC — they will determine how these vaccines are used."
"The ACIP members who were fired were highly qualified," Durbin says. "Right now it's not clear how recommendations would be made for the fall."
She notes Kennedy "could reconvene the ACIP committee that he disbanded at any time, as long as it meets the charter."
If the agencies Kennedy oversees do approve and recommend the new vaccine, Moderna says it could be available for the next flu season.
NPR Health Correspondent Rob Stein contributed to this report.
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