The Centers for Disease Control and Prevention recommended on Tuesday that Americans who received two doses of the Pfizer-BioNTech coronavirus vaccine seek a booster shot five months after the second shot, and not wait six months, as earlier guidance had said.
The agency also recommended that some immunocompromised children ages 5 to 11 receive an additional primary vaccine shot 28 days after the second shot, matching the guidance for similar people 12 and older. Pfizer’s vaccine is the only one authorized for pediatric use in the United States.
The endorsements come on the heels of the authorization of the same steps by the Food and Drug Administration on Monday.
The F.D.A. also cleared 12- to 15-year-olds to receive boosters of the Pfizer-BioNTech vaccine. The C.D.C.’s vaccine advisory committee is set to meet Wednesday to discuss whether to recommend that step.
The C.D.C. and the F.D.A. share responsibility for setting the nation’s vaccine policy, and have worked to present a unified front in their reviews of booster shots. If the advisory committee does follow the F.D.A.’s lead, the C.D.C.’s director, Dr. Rochelle P. Walensky, is expected to quickly sign off on the recommendation.
The moves come at a time when the fast-spreading Omicron variant is infecting record numbers of Americans each day, and many hospitals in the United States are already deluged with Covid-19 patients with the earlier Delta variant.
Federal guidance has not changed for when to seek booster shots after initially receiving the Moderna vaccine (6 months after the second shot) or the Johnson & Johnson vaccine (2 months after the single shot).
More than 70 percent of people in the United States who are 12 or older have been fully vaccinated, according to the C.D.C.
In total, at least 1.9 million adolescents between 12 and 15 have tested positive for the virus, according to the C.D.C. Children who get infected with the coronavirus are less likely to develop serious illness than adults are, but they can still become very sick and even die.
The F.D.A. noted that data from Israel showed no serious safety concerns in thousands of 12- to 15-year-olds who received a third dose of the Pfizer vaccine. There were no reports of myocarditis, a very rare side effect linked to the Pfizer and Moderna vaccines that has been seen mostly in younger men. The condition involves inflammation of muscle tissue in the heart.