The Food and Drug Administration approved Moderna’s mRNA flu vaccine, mFlusiva, on Wednesday, opening the U.S. market to the first flu shot built on the platform and clearing use for adults 50 to 65 and adults 65 and up. Moderna said the vaccine will be available for this fall’s flu season, but the approval for older adults comes with an added clinical trial requirement.
In a late-stage trial, mFlusiva was about 27% more effective than a standard flu shot. Moderna said its platform can move from picking the strain to rollout in two to three months, compared with about six months for traditional flu shots.
Dr. Ofer Levy
Dr. Ofer Levy, director of the Precision Vaccines Program at Boston Children’s Hospital, pointed to the strain-selection problem with a line that cuts to the core of flu vaccine timing: “If you’re choosing the strain half a year before, how good can we be at sharpshooting?” He also said of traditional flu shots, “We wish it were higher, quite frankly,” after noting the 22% to 56% range cited for them.
The approval lands after the FDA’s independent vaccine advisory committee unanimously recommended the vaccine in June. It also follows a reversal by the FDA this year, after the agency initially refused to review Moderna’s application before changing course a week later. Moderna’s application was moving through a process that had already drawn attention because the company had also secured approval for a combination flu and Covid vaccine from the European Union in April.
Moderna and FDA
The trial behind mFlusiva included more than 40,000 older adults across 11 countries, including the U.S. Moderna said side effects such as injection-site pain, fatigue and headaches were more common in the mFlusiva group, but were still mild to moderate. The added trial requirement for adults 65 and up means the company must keep building the evidence base for the group most likely to face severe flu.
For readers 50 and older, the practical change is simple: a new vaccine option is now cleared for this fall, and it uses a platform that Moderna says can be produced faster than conventional flu shots. For older adults, the approval opens access now, while the extra trial condition means the full regulatory path in that age group is not finished.
Robert F. Kennedy Jr.
The approval also comes while Robert F. Kennedy Jr., the HHS secretary, has repeatedly criticized mRNA technology and called the Covid vaccines “the deadliest vaccine ever made.” That stance sits alongside the FDA’s decision to back Moderna’s flu shot anyway, giving the vaccine a path into routine use even after the agency’s earlier refusal to review it.
