FDA sets new COVID booster guidelines requiring trials for approvals for healthy adults

The U.S. Food and Drug Administration plans to require new clinical trials for approval of annual COVID-19 boosters for healthy Americans under 65, effectively limiting their availability this fall to older adults and those with a higher risk of developing severe illness, FDA leaders said on Tuesday.

FDA Commissioner Marty Makary and top U.S. vaccines regulator Vinay Prasad said based on data from tests that measure immune response in patients, they anticipate that the FDA will be able to approve the boosters for adults over the age of 65 years. It would also be available for everyone over the age of six months with one or more risk factors that put them at high risk for severe COVID-19 outcomes, they said in a piece published in the New England Journal of Medicine on Tuesday.

But for healthy people between the ages of six months and 64 years, the FDA expects it would need randomized, controlled trials for drugmakers to get approval for annual shots. Prasad and Makary said that saline could be used as placebo in those trials. 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.

But Prasad and Makary say the studies are needed to provide evidence that annual shots for healthy younger Americans are evidence-based. "We simply don't know whether a healthy 52-year-old woman with a normal BMI who has had Covid-19 three times and has received six previous doses of a Covid-19 vaccine will benefit from the seventh dose," Prasad and Makary wrote in the piece. "This policy will compel much-needed evidence generation."

There are currently three approved vaccines for COVID-19 in the U.S.: messenger RNA-based shots made by Moderna Inc and by Pfizer and Germany's BioNTech, and a protein-based vaccine made by Novavax Inc. "This is quite reasonable. The really high risk people - people over 65, people with chronic medical conditions - can still get the vaccine," said Dr. David Boulware, an infections disease specialist at the University of Minnesota.

Boulware said he believed it was unlikely that vaccine makers will conduct the clinical trials to receive the broader approval. "This is going to be hundreds of millions of dollars, so they're not going to do the trial in a young population because the sample size would be huge to show benefit. I think its unlikely to be done," he said.

U.S. Health and Human Services Secretary Robert F. Kennedy Jr. is a vaccine skeptic, who has long sown doubts about the safety and efficacy of the shots. Makary and Prasad have been critical in the past of the approval process and the evidence supporting the necessity of annual COVID-19 shots for many Americans. They said the U.S. policy has been more aggressive than policies followed in Europe, Mexico and Canada.

Still, they acknowledged that the 2020 development of the shots were 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." 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.

Novavax's shot was approved last week after the FDA missed the April 1 target to make a decision on the vaccine. The FDA already limited its use to older adults and people over the age of 12 with conditions that put them at risk due to the illness. According to the U.S. Centers for Disease Control and Prevention, a wide list of conditions constitutes an additional risk, ranging from various illnesses, such as diabetes and heart disease, to behaviors like physical inactivity and substance abuse.

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

(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)