FDA tightens requirements for COVID vaccine, adding trials for healthy adults

FDA Commissioner Marty Makary and top U.S. vaccines regulator Vinay Prasad wrote in the New England Journal of Medicine that the benefit of repeated annual shots for healthy adults was uncertain after several years of the virus circulating and vaccines being available.

They also said that the U.S. was an outlier among high-income nations in recommending yearly shots for healthy adults.

"At-risk Americans can be reassured that they will be covered by such approvals. At the same time, we want more evidence at the U.S. Food and Drug Administration," Prasad told scientists at the FDA during a livestreamed presentation.

"We want to know more about what these products are doing, especially as we enter the seventh, eighth and ninth dose," he said.

Health Secretary Robert F. Kennedy Jr., a long-time vaccine skeptic whose department oversees the FDA, has been remaking the U.S. health system to align with President Donald Trump's goal of dramatically shrinking the federal government. Some 20,000 people have left the department as part of mass layoffs.

Makary and Prasad have been critical of U.S. COVID vaccine policies and indicated that they were under review.

Jefferies analyst Michael Yee said the new guidance essentially does not change vaccine policy for older and high-risk Americans, putting investors at ease.

Shares of COVID-19 vaccine makers Moderna were up 7.6% at $28.40, Pfizer rose 1.9% to $23.45 and U.S. ADRs of Germany's BioNTech rose 4%. Novavax shares were up 1.5% at $7.86.

Pfizer said it was evaluating the details shared today and that discussions with the FDA are ongoing. The other companies did not immediately respond to requests for comment.

Makary and Prasad said they expect the FDA will be able to approve the boosters for adults over the age of 65 years based on data from tests that measure immune response in patients.

The shots would also be available for everyone over the age of six months with one or more issues that put them at high risk for severe COVID-19 outcomes, they said.

But for healthy people between the ages of six months and 64 years, the FDA expects it would require formal clinical trials for drugmakers to get approval for annual shots.

Prasad said all the COVID vaccine makers will be asked to conduct placebo-controlled trials in healthy 50 to 64 year olds and encouraged to conduct them in very young children.

He said that he does not expect that new trials will be necessary every year, just when there are major shifts in the virus.

Vaccine makers have argued that because COVID vaccines have been changed annually to match the circulating strain of the virus, new placebo-controlled trials could delay availability of the shots until after their usefulness has passed.

The American Academy of Pediatrics said it had serious concerns about the new framework and its potential impact on insurance coverage.

"Taking away coverage means taking away choice for families," Dr. Sean O'Leary, chair of the AAP Committee on Infectious Diseases, said in a statement.

Expensive Trials

 Dr. David Boulware, an infectious disease specialist at the University of Minnesota said the new framework is "quite reasonable. The really high risk people - over 65, people with chronic medical conditions - can still get the vaccine," he said.

Boulware said he believed it was unlikely vaccine makers will conduct the clinical trials to receive the broader approval in younger adults, saying it would require large enrollment and could cost "hundreds of millions of dollars."

Makary and Prasad - both new to the FDA this year - have been critical in the past of the approval process and the evidence supporting the necessity of annual COVID-19 shots for many Americans.

Still, they acknowledged that the 2020 development of the shots was a major scientific, medical, and regulatory accomplishment. They also called the measles-mumps-rubella vaccine a vital immunization and said it had been "clearly established as safe and highly effective."

Kennedy, who long promoted claims that vaccines are linked to autism, contrary to scientific evidence, has launched a study to find the causes of a rise in its prevalence.

COVID vaccines are significant products for drugmakers, even as uptake has fallen post-pandemic. In 2024, U.S. sales of COVID boosters, sold primarily by Pfizer and Moderna, topped $3.5 billion.

When Novavax's shot was approved last week, the FDA limited its use to older adults and people over the age of 12 with conditions that put them at risk of severe illness.

According to the U.S. Centers for Disease Control and Prevention, a wide list of conditions constitutes an additional risk including obesity, diabetes and heart disease, as well as behaviors like physical inactivity and substance abuse.

Makary and Prasad said that estimates suggest that some 100 million to 200 million Americans would have access to the annual shots under these new terms.

The FDA's vaccine advisory committee is scheduled to meet later this week to discuss which variant of the coronavirus vaccine makers should target ahead of the COVID inoculation season this year.