A new type of flu shot is coming after FDA approves mRNA-based vaccine

The Food and Drug Administration has approved the first mRNA-based flu vaccine, paving the way for a new type of shot that will be available for adults 50 and over looking to get immunized against the respiratory illness, Moderna announced Wednesday evening.

The agency granted approval to Moderna’s vaccine for adults ages 50 to 64 and accelerated approval for those 65 and older with a commitment to further study the shot in older adults in a post-marketing study, according to Moderna. The company said the new shot will probably be available in select retailers in the coming weeks. A price was not immediately available.

Medical experts have expressed hope that mRNA vaccines could make it easier for manufacturers to respond quicker to changes in the flu strain because they are faster to develop than traditional shots.

“Flu remains a significant public health challenge, and mFLUSIVA provides an important new option for America’s seniors,” Moderna CEO Stéphane Bancel said in a press release. “This approval also reflects the ongoing potential of our mRNA platform to help address important public health challenges through continued scientific innovation.”

The decision puts an end to a high-profile back-and-forth over the shot and comes despite Health Secretary Robert F. Kennedy Jr.’s past criticism of mRNA technology used to develop the coronavirus shots. In early February, Vinay Prasad, the FDA’s vaccine chief at the time, argued in a letter that the shot lacked an “adequate and well-controlled” study, and said the company’s application was “on its’ face, inadequate for review.”

The decision shocked the company, and the agency quickly reversed course to review the shot under a revised approach amid pushback from vaccine experts who said the decision raised questions around shifting guidance for vaccine makers. Moderna met with the FDA in mid-February and proposed the compromise of seeking full approval for the younger cohort and accelerated approval for older adults with a pledge to further study the shot for those 65 and over.

Flu vaccines are updated annually, and their effectiveness depends on how well-matched they are to the circulating strain. They are typically available starting mid-to-late summer.

Moderna’s new mRNA vaccine is for adults ages 50 and over, and it is expected to be available soon in certain stores in the coming weeks.

In a June presentation, the FDA said available data for seasonal influenza mRNA vaccines shows “generally robust immune responses.” The agency has said there is a need for more effective flu vaccines and technologies capable of quickly reformulating to match circulating strains.

Moderna’s mRNA shot was nearly 27 percent more effective against seasonal flu than a standard flu shot, according to clinical trial data.

The mRNA vaccine is associated with higher rates of temporary injection-site pain and fatigue, according to the FDA. Data directly comparing it to the traditional high-dose flu vaccines — which are preferentially recommended for those age 65 and over — requires further evaluation, the agency said.

Moderna has agreed to study the new shot for confirmation of clinical benefit for those 65 and over.

“If approved, I would strongly consider [the mRNA shot] in the 50-64 group given documented superiority in effectiveness to normal dose flu vaccines approved for those ages, and especially for those with underlying diseases,” Jesse Goodman, who previously served as the FDA’s top vaccine regulator, wrote in a text message before the FDA signed off on the vaccine.

For those 65 and over, Goodman said, the vaccine could be “considered as an alternative option.”

Medicare would cover the shot, according to Jennifer Kates, a senior vice president at KFF, a health policy research and news organization. But the question of insurance coverage for those who haven’t yet turned 65 is complicated and could depend on where a person lives.

Major insurers have previously indicated they will continue to cover vaccines. However, sign-off from a federal vaccine advisory panel can influence coverage in certain states, though some are moving away from requiring the panel’s recommendation. A federal judge has thrown the panel, known as the Advisory Committee on Immunization Practices, into legal limbo, ruling that Kennedy improperly reconstituted it after firing all of its members last year. As a result, the panel is not expected to meet soon to consider the Moderna vaccine.

It’s difficult to predict how broadly pharmacies would stock the newly approved mRNA flu vaccine in the absence of recommendations from ACIP and the Centers for Disease Control and Prevention, according to Brigid Groves, a vice president at the American Pharmacists Association. However, pharmacists’ authority to order and administer vaccines in many states is no longer directly tied to ACIP recommendations, meaning “authority may be less of a barrier than it would have been in the past,” she said.

The decision to approve Moderna’s mRNA vaccine is likely to face pushback from some of Kennedy’s allies who have expressed skepticism over mRNA-based coronavirus shots. Kennedy, the founder of a prominent anti-vaccine group, has a lengthy history of disparaging vaccines and once falsely referred to the coronavirus shot as the “deadliest vaccine ever made.”

During the pandemic, the coronavirus shots, including one from Moderna, were praised because the technology helped deploy vaccines at record speed. President Donald Trump referred to the effort at the time as a “modern-day miracle.” Medical experts say the vaccine has been proven to be safe and effective.

But since then, anti-vaccine advocates and some leaders in the Trump administration’s second term, including Kennedy, have cast doubt on the technology. Last year, Kennedy had sought to wind down some mRNA vaccine projects supported by the federal government, which his health department said was worth nearly $500 million.

In mid-June, the FDA’s vaccine advisers voted unanimously that the Moderna shot’s benefits outweigh the risks for adults ages 50 to 64, as well as for those 65 and older. The agency is not required to follow the advice of its independent experts, but it often does.

The criticism of the shot from Prasad, FDA’s former vaccine chief, had centered on its trial design. Moderna had conducted two late-stage trials, one of the final steps before seeking approval for the mRNA flu vaccine. In one trial, more than 40,000 participants received either a dose of the experimental mRNA flu vaccine or a standard dose of an existing flu shot. In a smaller trial, participants received a dose of the mRNA vaccine or a high-dose influenza shot recommended for adults 65 and older to assess the ability to trigger an immune response.