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FDA leaders say studies needed to show evidence of benefit

of

annual shots for healthy adults

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FDA leaders say 100 million-200 million Americans would

still be

eligible for annual shots

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FDA leaders say U.S. COVID policy has been more aggressive

than

Europe

By Michael Erman

NEW YORK, May 20 (Reuters) - 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 ( MRNA )

and by Pfizer ( PFE ) and Germany's BioNTech, and a

protein-based vaccine made by Novavax Inc. ( NVAX )

"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 ( PFE ) and Moderna ( MRNA ) - topped $3.5

billion.

Novavax's ( NVAX ) 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.