Roughly 130 million Americans aged 18 and over have received a shot, representing 50.4 percent of the adult population, according to the Centers for Disease Control and Prevention (CDC).
Around 84 million adults are fully vaccinated - 32.5 percent of the adult population.
The United States is a world leader in vaccinations, but a recent surge in new daily infections prompted top pandemic advisor Anthony Fauci to warn Sunday that the country remains in a "precarious position."
White House efforts to speed up vaccinations hit a snag when health authorities reported six cases of young women developing a clotting disorder after taking the Johnson & Johnson shot.
Of nearly 7 million doses of J&J/Janssen #COVID19 Vaccine given in the US, a small number of cases of a rare & severe type of blood clot have been reported in people after receiving the vaccine. CDC & @US_FDA recommend a pause as we review data. More: https://t.co/SVTRkBgIET pic.twitter.com/QF5po3vTQ4— CDC (@CDCgov) April 14, 2021
A government-convened expert panel has been assessing the issue and a decision on whether to end a pause on J&J vaccinations is likely by Friday, Fauci told ABC's "This Week."
"I believe we'll get back with it," he said, though he added that there may be some restrictions or warnings on its use.
The CDC says 109 million doses of Pfizer's vaccine have been administered, along with 92 million doses from Moderna and 7.9 million doses of Johnson & Johnson's vaccine.