The Biden administration called for a third Covid-19 shot starting in the fall for adults who were fully vaccinated with the two-shot regimen, citing the threat from the highly contagious Delta variant and concerns over data showing initial immunity wanes over time.
The announcement Wednesday means that booster shots will soon be available for the more than 155 million people in the U.S. who have been fully vaccinated with messenger-RNA vaccines by Pfizer Inc. and partner BioNTech SE or by Moderna Inc.
The booster shot will be administered about eight months after the second dose for people ages 18 and older. The U.S. government said it is preparing to offer boosters starting the week of Sept. 20.
U.S. Surgeon General Vivek Murthy said the booster shots would help the country stay ahead of the virus, even though the current two-dose regimens are effective. He cited emerging evidence indicating that the vaccines lose some of their power over time and the Delta variant warrants the extra boost.
“Having reviewed the most current data, it is now our clinical judgment that the time to lay out a plan for Covid-19 boosters is now,” Dr. Murthy said.