Americans who have been fully vaccinated against the coronavirus don’t need to wear protective masks outdoors any longer, the Atlanta-based Centers for Disease Control and Prevention said Tuesday.

The CDC is continuing to recommend masks for indoor gatherings or crowded outdoor events. Masks are no longer required for such activities as outdoor walking, running, hiking or biking; small outdoor gatherings with fully vaccinated family and friends; small outdoor gatherings with a mixture of fully vaccinated and unvaccinated people; and dining at outdoor restaurants with friends from other households.

Fully vaccinated people can also attend “a crowded, outdoor event, like a live performance, parade, or sports event,” as long as they remain masked, according to the CDC.

For most of the past year, the CDC had been advising Americans to wear masks outdoors if they are within 6 feet of each other.

The CDC released the new guidelines shortly before President Joe Biden was set to provide an update on the pandemic.

“Earlier today the CDC made an important announcement. Starting today if you are fully vaccinated and outdoors, not in a big crowd, you can go without a mask,” the president said, noting that masks are still required in crowded spaces, such as a music concert, regardless if it is outdoors.

But when it comes to gathering with a group of friends in the park or going for a picnic, “you can do this without a mask,” he said, noting that the federal health agency was able to change its guidance because the “odds of getting or giving the virus are very low out in open air.

“If you are vaccinated you can do more things more safely indoors and outdoors,” the president continued. “For those who haven’t gotten it, this is another good reason to get vaccinated. It’s about saving your life [and the lives] of those around you; it’s about getting back to normal life.”

Over the weekend, the CDC updated its guidelines and recommendations for summer camps just weeks before many camps resume operations in mid-May.

Children going to camp this summer can be within 3 feet of each other in the same-group settings, but they must wear masks at all times. The only times children should remove their masks is when they are swimming, napping, eating or drinking; they should be spaced far apart for these activities, positioned head to toe for naps and seated at least 6 feet apart for meals, snacks and water breaks.

“It’s the return of freedom,” said Dr. Mike Saag, an infectious disease expert at the University of Alabama at Birmingham. “It’s the return of us being able to do normal activities again. We’re not there yet, but we’re on the exit ramp. And that’s a beautiful thing.”

More people need to be vaccinated, and concerns persist about variants and other possible shifts in the epidemic. But Saag said the new guidance is a sensible reward following the development and distribution of effective vaccines and about 140 million Americans stepping forward to get their shots.

Unvaccinated people — defined by the CDC as those who have yet to receive both doses of the Pfizer or Moderna vaccine or the one-shot Johnson & Johnson formula — should wear masks at outdoor gatherings that include other unvaccinated people. They also should keep using masks at outdoor restaurants.

The coronavirus has killed more than 572,000 people in the U.S., the highest death toll in the world.

Dr. Babak Javid, a physician-scientist at the University of California, San Francisco, said the new CDC guidance is sensible. “In the vast majority of outdoor scenarios, transmission risk is low,” he said.

Javid has favored outdoor mask-wearing requirements because he believes they increase indoor mask-wearing, but he said Americans can understand the relative risks and make good decisions.

“The key thing is to make sure people wear masks indoors” while in public spaces, he said.

He added: “I’m looking forward to mask-free existence.”

“The timing is right because we now have a fair amount of data about the scenarios where transmission occurs,” said Mercedes Carnethon, a professor and vice chair of preventive medicine at Northwestern University’s Feinberg School of Medicine in Chicago.

What’s more, she said, “the additional freedoms may serve as a motivator” for people to get vaccinated.

The Associated Press contributed to this report.