In advance of a scientific meeting on Thursday, officials proposed offering new shots to Americans each fall, a strategy long employed against the flu.
Americans may be offered a single dose of a Covid vaccine each fall, much as they are given flu shots, the Food and Drug Administration announced on Monday.
To simplify the makeup and timing of the shots, the agency also is proposing to retire the original vaccines and to offer only bivalent doses for primary and booster shots, according to briefing documents published on Monday.
The proposal took some scientists by surprise, including a few of the F.D.A.’s own advisers. They are scheduled to meet on Thursday to discuss the country’s vaccine strategy, including which doses should be offered and on what schedule.
“I’m choosing to believe that they are open to advice, and that they haven’t already made up their minds as to exactly what they’re going to do,” Dr. Paul Offit, one of the advisers and director of the Vaccine Education Center at Children’s Hospital of Philadelphia, said of F.D.A. officials.