(Bloomberg) -- U.S. schools should maintain mask requirements at least through the end of the academic year, the Centers for Disease Control and Prevention said in its latest guidance, even after saying fully vaccinated adults can safely shed face coverings in most settings.

“Universal and correct use of masks should be required” at K-12 schools providing in-person instruction, the CDC said in a statement Saturday. “Physical distancing should be maximized to the greatest extent possible.”

That includes creating distance between children on school buses when possible and ensuring that “teachers and staff use proper handwashing and respiratory etiquette,” according to the agency.

The CDC said it’s recommending that schools apply the existing guidance because students won’t be fully vaccinated by the end of the 2020-2021 school year and youth under age 12 aren’t eligible for shots yet. That will allow schools that reopened to stay open, the agency said.

“Evidence suggests that many K-12 schools that have strictly implemented prevention strategies have been able to safely open for in-person instruction and remain open,” the CDC said.

President Joe Biden presented the shift in guidance for fully-vaccinated adults on Thursday, signaling a turning point for a nation weary from a coronavirus pandemic that’s killed more than 585,000 people in the U.S. “The rule is very simple: Get vaccinated or wear a mask until you do,” he said.

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