Agency leaders said there was evidence to justify approval only for older people and those with medical conditions. Many others may not be able to get the shots. The Food and Drug Administration will permit use of Covid vaccines by adults over 65 and those with certain medical conditions in the fall, but may require additional studies before approving the shots for healthy Americans younger than 65, agency officials said on Tuesday.
At this point, the additional doses offer “uncertain” benefits to many young and middle-aged people who have already been vaccinated or have had Covid, Dr. Vinay Prasad, the F.D.A.’s vaccine division chief, and Dr. Martin Makary, the agency’s commissioner, wrote in The New England Journal of Medicine.
“The F.D.A. will approve vaccines for high-risk persons and, at the same time, demand robust, gold-standard data on persons at low risk,” the officials wrote.