The U.S. Centres for Disease Control and Prevention (CDC) on Thursday advised that fully vaccinated people do not need to wear face masks outdoors and can avoid wearing them indoors in most places.
The new rules, the agency said, will allow life to begin to return to normal.
The CDC, which hopes the guidance will prod more Americans to get vaccinated, also said fully immunised people will not need to physically distance in most places.
The turnaround came just 16 days since CDC issued revised guidance that left many restrictions in place for vaccinated people.
The agency came under fire in March for initially discouraging immunised grandparents to fly to visit loved ones.
CDC Director Rochelle Walensky said the new guidance was based on a sharp reduction in cases, expansion of vaccines to younger people and vaccine efficacy against coronavirus variants.
“We followed the science here,” Walensky.
President Joe Biden emerged at the White House for remarks without a mask. “I think it’s a great milestone, a great day,” he said.
“If you’re fully vaccinated and can take your mask off, you’ve earned the right to do something that Americans are known for all around the world: greeting others with a smile,” he said.
Biden flashed a brief smile himself.
The U.S leader earlier shed his mask during a meeting with lawmakers, Republican Senator Shelly Moore Capito told reporters.
Some journalists at the White House also removed their masks.