After FDA green lights a second COVID booster, official says another could come in the fall

A few hours after the FDA authorized a fourth dose of the Moderna and Pfizer-BioNTech COVID-19 vaccines, one of its top experts hinted that a fifth dose may be on its way in the fall.

“I don’t want to shock anyone, but there may be a need for people to get an additional booster in the fall,” Peter Marks, the director of the FDA’s Center for Biologic Evaluation and Research, said in a virtual session with reporters on Tuesday afternoon.

Marks said that an FDA advisory committee will discuss the matter next week. If another booster is authorized in the fall, it could be one that is tweaked to defend against a particular coronavirus variant or a mixture of variants, he added.

“It’s not actually clear yet what the optimal booster should be,” Marks said.

While cases are on the decline in the U.S., recent surges of the omicron BA.2 subvariant in the U.K. and a few countries in Asia have put experts on alert. Marks said the added level of protection provided by another booster dose figured into the FDA’s decision on Tuesday.

“We’re hoping by taking this action, we will help allow people to take steps to protect themselves should we have another wave to come through this country,” Marks said.

Earlier on Tuesday, the U.S. regulator signed off on a fourth dose for those 50 and older and a fifth shot for those who are immunocompromised. A fourth dose was endorsed for the immunocompromised last fall and made available to those persons last month.

Meanwhile, many Americans are awaiting a decision from the FDA on whether to allow vaccines for young children. Moderna’s vaccine has yet to be cleared for kids under age 6, while Pfizer’s shot is awaiting clearance for those younger than 5.

Marks said that experts are disappointed in the vaccination rate among U.S. children who have been authorized to receive vaccines and that the agency must be able to provide clear evidence that the benefits outweigh the risks before granting the approvals.

“This is the age range when people are most concerned about potential side effects,” Marks said. “We have to do our job extremely well to make sure there is very good evaluation of the safety and effectiveness so when we make our recommendation people will trust it.”