RENO, Nev. (AP) — Nevada is adopting new mask-wearing guidance the Centers for Disease Control and Prevention announced Thursday for fully vaccinated people, allowing them to stop wearing masks outdoors in crowds and in most indoor settings.

The updated guidance is effective immediately in Nevada under a directive Gov. Steve Sisolak signed May 3 that aligned the state’s mask usage with the CDC recommendations, including any subsequent guidance the center issues, state health officials said.

Nevada also started making COVID-19 shots available to children as young as 12 for the first time on Thursday after federal health advisers endorsed the use of Pfizer’s vaccine in kids.

Sisolak said each county has had the authority to establish its own social distancing requirements since May 1. He said private businesses, entities and organizations may have mask policies that are more restrictive than the CDC guidance.

“COVID-19 is still very much a threat in our state and many Nevadans may choose to continue using masks based on their and their families’ personal health concerns,” Nevada's Health Response team said in a statement.

The state Gaming Control Board said casinos should see the governor's directive as a baseline.

“Licensees may have mask policies that are more restrictive than the CDC guidance," the regulatory board said, and "are encouraged to post signage with the latest CDC mask guidance for vaccinated and unvaccinated guests.”

The regulatory board said it “neither requires nor prohibits gaming licensees from confirming patron vaccination."

Earlier Thursday, President Joe Biden and his staff appeared in the Rose Garden at the White House without masks while he heralded the new guidance.

“Today is a great day for America,” Biden said. “If you are fully vaccinated, you no longer need to wear a mask ... Get vaccinated — or wear a mask until you do.”

The guidance still calls for wearing masks in crowded indoor settings like buses, planes, hospitals, prisons and homeless shelters. But it will help clear the way for reopening workplaces, schools and other venues — even removing the need for social distancing for those who are fully vaccinated.

The new guidance is likely to open the door to confusion because there is no surefire way for businesses or others to distinguish between those who are fully vaccinated and those who are not.

Nevada neither requires nor prohibits private entities from confirming the vaccination status of individuals, health official said. They encouraged employers and organizations to post signs with the latest CDC mask guidance for vaccinated and unvaccinated guests.

Meanwhile, more than 177,000 Nevada residents are in the 12-16 age group newly eligible for the vaccine, state health officials said.

“It’s a very big deal,” said Karissa Loper, chief of Nevada’s Bureau of Child, Family and Community Wellness,

“Kids, especially adolescents and teens, have more social contact and risk of spreading the virus making it especially important to get them vaccinated," she said Thursday.

As of Wednesday, 30% of all Nevada residents have been fully vaccinated and 37.7% of state residents 16 and older. Vaccinations have been initiated with the first shot for 37.8% of all residents and 47.7% of those 16 and older.

Pfizer’s vaccine has been used for months in people 16 and older, and earlier this week the Food and Drug Administration cleared its use for those as young as age 12.

To date, 10% of Nevada’s more than 2 million total COVID-19 cases have been in the 10-19 age group, Loper said.

The American Academy of Pediatrics has said that children now account for one-fifth of all COVID-19 cases nationally. A year ago, they made up only 3% of the total. About 1.5 million cases were reported nationally among individuals between ages 11 and 17 between March 1, 2020, and April 30 this year.

Loper said that’s likely because the virus is more likely to target children as more and more adults get vaccinated.

By 12 p.m. Thursday, Washoe County health district officials reported that they had already made appointments for more than 300 people 12 to 15 at its drive-thru post at the Reno-Sparks Livestock Events Center.

Vaccine recipients 12 to 17 are required to be accompanied by a parent or guardian. Appointments are recommended but not required.

“This gives the U.S. another resource in fighting COVID-19,” said Dr. Bayo Curry Winchell, medical director of urgent care at Saint Mary’s hospital in Reno.

She added: “It’s reassuring to know that children will have another level of protection during summer activities and the upcoming school year."

The Southern Nevada Health District began offering the Pfizer shots to people 12 and older at the Las Vegas Convention Center and many other sites on Thursday.

“The more people that are vaccinated in our community, the better protected everyone will be,” said Dr. Fermin Leguen, district health officer for the Southern Nevada Health District.