New York state health officials said Friday that mask-wearing will be optional in K-12 schools starting Monday, but the country’s largest school system, New York City, plans to keep its universal mask policy in place.

New York will move forward with the plan unless the CDC provides data or science that “contradicts” that change before Monday, state Health Commissioner Howard Zucker wrote in a Friday letter to the U.S. Centers for Disease Control and Prevention.

Republicans had urged Cuomo to drop the mandate this week.

The release of the letter on Friday afternoon caught school leaders and teachers unions by surprise.

“Announcing on a Friday afternoon that masks will now be optional for both vaccinated and unvaccinated people in schools starting Monday — with only three weeks remaining in the school year — is whiplash-inducing news,” New York State United Teachers President Andy Pallotta said in a statement.

Pallotta urged school districts to evaluate “local conditions and connect with their educators and parents to decide the best course of action for protecting their school community.”

Schools and camps can choose to implement stricter rules, according to Zucker.

New York City will do so, according to Danielle Filson, spokesperson for the New York City Department of Education.

“The health and safety of our students, educators and staff remain our top priority,” she said. “Per state guidance, local districts may implement standards that make the most sense for their communities, and we are continuing with our universal mask policy at our schools.”

Meanwhile, the CDC told The Associated Press that it recommends schools and childcare facilities continue to follow COVID-19 prevention strategies, such as consistent indoors mask use, for the rest of the 2020-2021 school year.

“Current evidence demonstrates that consistent mask use indoors among people two and older who are not fully vaccinated, along with other preventive strategies, is key to reducing the spread of COVID-19,” Public Affairs Specialist Jade Fulce said in an email.

“The recommendation to continue with these prevention strategies is based on youth aged 12-15 not being able to be fully vaccinated before the end of the current school year and youth under 12 not yet being eligible for vaccinations,” she added. “Additionally, schools need time to make systems and policy adjustments.”

The Cuomo administration started requiring face masks to be worn “at all times” in school in early April.

That was a shift from the state’s previous stance of letting local governments decide whether to require masks in schools.

Rates of COVID-19 infections, hospitalizations and deaths are plummeting in New York, while vaccination rates are ticking up.

Still, Zucker’s letter to the CDC didn’t cite any data about why New York is now reversing the mask mandates in schools.

Republican Senate Minority Leader Rob Ortt wrote Cuomo a Thursday letter urging him to drop the mandate: “Many of our school buildings do not have air conditioning, so to require face coverings in dangerous temperatures will be detrimental not only to their physical health, but also to their ability to focus and learn.”

Zucker said the state wanted to “align our school and camp mask guidance.”

According to Zucker, the state Department of Health will “strongly” encourage but not require mask use for students, campers, and staff who are not fully vaccinated starting Monday.

Masks won’t be required outdoors, though individuals who aren’t fully vaccinated will be encouraged to wear a mask “in certain higher-risk circumstances.”

“Both indoors and outdoors, students, campers, and staff who are fully vaccinated do not need to wear masks,” Zucker wrote.

(AP)