Health Officials Advise Biden to Scale Back Covid-19 Booster Shots Plan For Now

“When that approval and recommendation are made,” the spokesman, Chris Meagher, said, “we will be ready to implement the plan our nation’s top doctors developed so that we are staying ahead of this virus.”

Less than three weeks ago, Mr. Biden said that contingent on F.D.A. approval, the government planned to start offering boosters the week of Sept. 20 to adults who had received their second shot of the Pfizer-BioNTech or Moderna vaccine at least eight months ago. That would include many health care workers and nursing home residents, as well as some people older than 65, who were generally the first to be vaccinated. Administration officials have said that recipients of the single-dose Johnson Johnson vaccine would probably be offered an additional shot soon as well.

Mr. Biden cast the strategy as another tool that the nation needed to battle the highly contagious Delta variant, which has driven up infection rates, swamped hospitals with Covid-19 patients and is now leading to an average of more than 1,500 deaths a day. “The plan is for every adult to get a booster shot eight months after you got your second shot,” he said on Aug. 18, adding: “It will make you safer, and for longer. And it will help us end the pandemic faster.”

But the announcement of a late September target date for starting the booster campaign set off alarm bells inside the F.D.A. — apparently playing a role in decisions by two of its top vaccine regulators, announced this week, to leave the agency this fall.

Both Dr. Woodcock and Dr. Walensky helped draft the plan and publicly endorsed it. Some public health experts have said that by doing so, they increased pressure on scientists weighing the evidence for boosters in their respective agencies to go along with the administration’s strategy.