The director of the Center for Disease Control and Prevention, Dr. Rochelle Walensky, is seen during a Senate Committee on Health, Education, Labor and Pensions hearing to discuss the ongoing federal response to COVID-19 on May 11 at the U.S. Capitol in Washington, DC. 2021.

Greg Nash | Pool | Reuters

CDC director Dr. Rochelle Walensky last week defended the agency’s decision to lift mask mandates for people fully vaccinated against the coronavirus as state and local health officials grapple with whether to follow suit.

“This was not permission to take off masks for everyone everywhere. This was a really scientifically motivated, individual assessment of your risk,” Walensky said on NBC’s Meet the Press on Sunday morning.

The Centers for Disease Control and Prevention updated their guidelines Thursday stating that it is safe for fully vaccinated Americans to remove their masks in most environments, whether they are outdoors or indoors. It is the first time in more than a year that the federal government has endorsed the shedding of masks and marks a major turning point for the pandemic.

“Right now, the data, the science, is showing us that it is safe for people who have been vaccinated to take their mask off. I, as the CDC director, made a promise to the Americans that if I knew I would teach you that science, and that’s what It’s Thursday, “said Walensky.

The agency’s recommendation has been criticized as being too ambiguous or rash. It’s also not mandatory, so states, communities, and corporations can choose whether or not to comply. There is also no definitive way of tracking who received a vaccine, and many places have to work on some kind of honor system.

“We ask people to be honest with themselves,” said Walensky. “If you are vaccinated and you don’t wear a mask, you’re safe. If you’re not vaccinated and you don’t wear a mask, you’re not safe.”

Some states and companies have already decided to keep mask mandates. New Jersey and Hawaii will ask people to continue wearing masks indoors. Some retailers, including Target, Gap, Home Depot, and Ulta Beauty, have also announced that they will be keeping the pandemic logs.

“Elementary workers are still being forced to play masked police for shoppers who are not vaccinated and who refuse to follow local COVID safety measures. Should they become the vaccination police now?” Said Marc Perrone, president of United Food and Commercial Workers Union in a statement shared with CNBC on Friday.

Others have praised the decision, saying it could encourage more people to get vaccinated against the virus as the pace of shots fired has slowed in recent weeks.

Illinois, Connecticut, Oregon, Pennsylvania, Washington, Minnesota, Nevada, Kentucky, and Oregon have all said they were relaxing their mask rules. Texas had canceled its mask mandates prior to the CDC’s recommendation.

In addition, officials from New York and California, two of the hardest-hit states, are currently reviewing the CDC’s changes and have not yet issued any guidance as to what means mandates remain.

As of Friday, more than 156 million Americans had received at least one dose of a Covid vaccine, according to the CDC. According to the agency, around 121 million people are fully vaccinated.