FDA authorizes fourth Pfizer Covid vaccine dose for people age 50 and

The Food and Drug Administration has authorized a fourth Pfizer Covid vaccine dose for everyone age 50 and older, amid uncertainty over whether an even more contagious version omicron will cause another wave of infection in the U.S. as it has in Europe and China.

Pfizer, in a statement on Tuesday, said the FDA also authorized a second booster shot for people age 12 and older who have compromised immune systems. Moderna is expected to receive a similar authorization from the FDA this week.

The FDA made the decision without a meeting of its vaccine advisory committee, a rare move the agency has made more frequently over the course of the pandemic to expand uses of Covid vaccines. The drug regulator’s authorization comes just two weeks after Pfizer and Moderna asked the FDA to permit a second booster shot based on data from Israel. The Centers for Disease Control and Prevention is expected to quickly sign off on the decision.

The FDA’s decision effectively bypasses its advisory committee on vaccines, which is scheduled to meet on April 6 to discuss the future of booster shots in the U.S. The vaccine experts are expected to hold a broad discussion about boosters and will not vote on a specific recommendation.

Dr. Paul Offit, a committee member, criticized the drug regulator for moving forward without holding an open meeting where the American public can hear experts weigh the data and make a recommendation to the FDA about the best path forward. The vaccine advisory committee’s recommendations are nonbinding, but they provide transparency for the public.

“It’s just sort of fait accompli,” Offit said of the FDA authorization. “So is this the way it works? We talk endlessly about how  we follow the science — it doesn’t seem to work out that way.”

The FDA has not called on the committee members to make a recommendation on booster shots since last fall when they voted in favor of a third Pfizer or Moderna dose for people age 65 and older and younger people at risk of severe Covid.

Health experts disagree on whether a fourth vaccine dose is needed right now, though the debate is nuanced. There is broader agreement that the elderly or immune compromised may benefit from additional protection. Another booster shot for young, healthy adults is more controversial, as they are less susceptible to severe illness from Covid.

Dr. Peter Hotez, a vaccine expert at Baylor College of Medicine in Houston, said some scientists believe the only purpose of the shots is to keep people out of the hospital. However, Hotez said vaccine policy should also seek to prevent infection and long Covid. The effectiveness of the third dose against hospitalization from omicron has also declined over time, he said.

The CDC published a study in February that showed the effectiveness of the third dose against emergency room visits declined from 87% to 66% against emergency room visits, and from 91% to 78% against hospitalization at four months after receiving the shot.

“That gives me pause…