The Centers for Disease Control and Prevention says that fully vaccinated adults can safely resume activities indoors or outdoors without masks or distancing, in gatherings large or small. The announcement marks a major milestone in the effort to emerge from the coronavirus pandemic in the United States.
CDC Director Dr. Rochelle Walensky announced the new guidance Thursday.
"You can do things you stopped doing because of the pandemic," Walensky said.
The new policy is based on recent real-world studies from Israel and the U.S. on people who've been vaccinated, she said.
In response to a question, Walensky said the federal mask requirement on public transportation remains in force for everyone, vaccinated or not – including on buses, trains, airplanes and in stations and airports.
"For travel, we are still asking people to continue wearing their masks," Walensky said. She said the policy continues to be under review.
However, under the new guidance fully vaccinated people can resume domestic travel without needing to get tested before or after, and they do not need to self-quarantine. They also do not need to quarantine following a known exposure so long as they are asymptomatic.
The CDC says masks may still be required by state, local, tribal or territorial laws as well as businesses and workplaces. But some local jurisdictions swiftly announced they would update their own regulations to conform with the CDC guidance, and more are expected to follow.
Unvaccinated people "remain at risk" of illness and death, Walensky said, and should remain masked and observe physical distancing.
Speaking in the White House Rose Garden on Thursday afternoon, President Biden said, "Today is a great day for America and our long battle with coronavirus." The president and Vice President Harris both smiled widely and did not wear masks.
"I think it's a great milestone, a great day," Biden said. "It's been made possible by the extraordinary success we've had in vaccinating so many Americans so quickly."
He praised the American people for how much they had endured since the beginning of the pandemic, including lost jobs and missed life events, and particularly the more than 580,000 lives lost to COVID-19.
Biden emphasized that the new rules only apply to those who are fully vaccinated. People are considered fully vaccinated two weeks after receiving the second dose of the Pfizer or Moderna vaccines, or two weeks after the single dose of the Johnson & Johnson shot.
Those not fully vaccinated should still wear a mask, the CDC said.
"We've gotten this far. Please protect yourself until you get to the finish line," Biden said. "Get vaccinated or wear a mask until you do."
In an interview Thursday with NPR's All Things Considered, Walensky said the new mask guidance was possible due to the effectiveness of the coronavirus vaccines, the drop in U.S. cases and universal vaccine availability in the U.S. for people age 12 and older.
Walensky noted that the Pfizer, Moderna and Johnson & Johnson vaccines are all 100% effective in preventing hospitalizations and deaths from COVID-19, even if they don't prevent 100% of coronavirus infections. They are also effective against the coronavirus variants circulating in the U.S., she said.
The CDC director said it would be safe for a fully vaccinated person to go into a grocery store, even if there were unvaccinated, unmasked shoppers there.
Walensky noted that the guidance will take some getting used to for many people.
"We have been doing this for 15 months at this point and not everybody's going to want to shed their masks immediately," she said. "It's going to take us a little bit of time to readjust."
NPR's Tamara Keith contributed to this report.