People who are vaccinated should still wear masks in crowded outdoor spaces as well as indoors, while those who are unvaccinated should continue wearing masks in all settings

Fully vaccinated Americans can go outdoors without masks in small social settings, the Centers for Disease Control said Tuesday in new guidance.

Once people have received all doses of a COVID-19 vaccine and waited the two weeks to reach fully efficacy, they can safely go walking, running, hiking or biking outdoors without a mask; attend small outdoor gatherings with vaccinated or unvaccinated people and dine outdoors with people from multiple households, the health agency said.

However, fully vaccinated people should still wear a mask indoors and in crowded outdoor settings such as concerts or baseball games. And unvaccinated people should continue to wear masks in all settings, except for at home.

"If you are fully vaccinated, things are much safer for you than those who are not yet fully vaccinated," CDC Director Dr. Rochelle Walensky said in a briefing on Tuesday.

The shift in guidance is based on growing data that shows that the chance of COVID-19 transmission while outdoors is low, combined with the increase in Americans who are fully vaccinated, she explained.

CDC mask guidance
People with and without masks walk around Central Park in New York City
| Credit: Alexi Rosenfeld/Getty

"There's increasing data that suggests that most of transmission is happening indoors rather than outdoors — less than 10% of documented transmission in many studies have occurred outdoors," Walensky said. "We also know that there's almost a 20-fold increased risk of transmission in the indoor setting."

"Coupled with the fact that we now have 37% of people over the age of 18 fully vaccinated, and the fact that our case rates are now starting to come down, motivated our change of guidance."

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Walensky added that she hopes the change in guidance will encourage more people to get vaccinated as some Americans still express hesitancy around the vaccines. According to a CBS News poll from this week, 22% of people said that they would not get the COVID-19 vaccine, and 18% said they might.

"I hope this message is encouraging for you," she said. "It shows just how powerful these vaccines are and our efforts to end this pandemic and why we are asking everyone to roll up their sleeves and get vaccinated. The science is clear. The COVID-19 vaccines have been through many transparent rigorous processes that continue to prove they are safe and effective. If you haven't already, please get vaccinated."

As of April 26, nearly 54% of the U.S. adult population has received at least one dose of a COVID-19 vaccine and 95,408,925 are now fully vaccinated, according to CDC data.

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