Federal Panel Recommends Booster Shots, Opening New Campaign Against the Virus

Scientific advisers to the C.D.C. endorsed additional doses of the Pfizer-BioNTech vaccine for older Americans but not for health care workers, in a possible rift with regulators.

An influential scientific panel on Thursday opened a new front in the campaign against the coronavirus, recommending booster shots of the Pfizer-BioNTech Covid vaccine for a wide range of Americans, including tens of millions of older people. But the experts declined to endorse additional doses for health care workers, teachers and others who might have higher exposure on the job.

The decisions were made by the C.D.C. panel, the Advisory Committee on Immunization Practices, in a series of votes, during which scientists agonized over their choices. The recommendations revealed deep divisions among federal regulators and outside advisers about how to contain the virus nearly two years into the pandemic.

Just a day earlier, the Food and Drug Administration authorized booster shots for certain frontline workers. But the C.D.C.’s advisers disagreed that the doses were needed by so many healthy people.