Students in Los Angeles public schools must wear a non-cloth mask with a nose wire at all times, including during sports, beginning Monday, the district announced in a letter to families this weekend.
Schools will give surgical-style masks to students and employees who need them, Los Angeles Unified's interim superintendent, Megan K. Reilly, wrote on Saturday.
The U.S. Centers for Disease Control and Prevention said this month that loosely woven cloth masks provide the least amount of protection.
LA County schools will also continue weekly testing for students and staff through February, Reilly said.
The interim superintendent said "in-school case rates dropped 7% since our baseline testing and current rates of students and staff are half of those in the general community due to the safety measures in place."
COVID-19 cases in LA County remain high, with 39,117 new daily cases reported Saturday.
As Los Angeles County schools ban cloth masks, masks will be optional starting this week at Fulton County schools in Atlanta.
In-person learning resumed in Fulton County last week.
"Maintaining face-to-face instruction is a top priority for our district," the school system said. "Though some employees have been out due to COVID, we intend to stay open, providing we have the staff to safely operate our schools."
Of everyone PCR tested in Fulton County between Jan. 3 and Jan. 16, 2022, 25.2% were positive, according to county data.