F.D.A. Panel Recommends Pfizer Boosters for Those Over 65 or at Risk

After Israel offered refresher therapies to the general population, there are now on average about half as many seriously or seriously ill patients as expected. She said boosters not only helped contain the spread of the infection, they also “actually saved lives.”

Dr. William C. Gruber, a senior vice president responsible for vaccine development at Pfizer, suggested that if the United States does not follow Israel’s lead, it could face more than five million more infections annually in people who take their second dose 10 months earlier compared to those who received the second injection five months earlier.

“Israel could hint at the future of Covid-19 in the US, and soon,” he said.

He said Pfizer’s data showed that a third shot elicited a robust antibody immune response that matched or far exceeded the response after the second dose. The data also shows that breakthrough infections in vaccinated Americans are more related to the decaying potency of the vaccine over time than to the Delta variant.

But committee members and some government officials were deeply skeptical. Dr. Philip Krause, one of the FDA vaccine experts who authored the journal medical review, criticized Pfizer’s presentation of data that had not been peer-reviewed or evaluated by the FDA, arguing that there were problems with modeling in a study that covered the case of the company underlined the effectiveness of the vaccine is an understatement.

Dr. Oliver, the CDC official, questioned attempts to draw a parallel between the United States and Israel, noting that Israel had only nine million inhabitants and was less heterogeneous than the United States. In particular, she also said Israel defines a serious case of Covid-19 more broadly than the United States, which may help explain why Israel is reporting more serious breakthrough infections among its vaccinated residents.

Another CDC official, Dr. Amanda Cohn asked Israeli officials why the spread of the virus there had intensified lately despite a widespread introduction of boosters. Dr. Alroy Price said the Jewish holidays, along with the start of the school year, had contributed to what she believed to be a temporary surge in cases.

Committee members also said they were concerned about a lack of safety data in younger recipients of a booster dose, as studies have shown a higher risk of myocarditis, an inflammation of the heart muscle, in young men who received the vaccine from Pfizer-BioNTech. Several asked if it would be better to wait for a booster vaccine specifically designed to fight off the Delta variant of the virus.