SAN FRANCISCO (AP) — The San Francisco school district has reversed course, saying it will require its 10,000 teachers and other staff to get vaccinated for COVID-19 or be tested weekly.

The announcement makes the San Francisco Unified School District the latest in California to issue a vaccine or testing mandate for staff, as schools across the state return to in-person classes amid a troubling surge in infections because of the highly contagious delta variant.

San Jose and Long Beach Unified school districts have issued similar requirements in recent days.

Los Angeles Unified, the state’s largest district, is requiring all students and employees to undergo weekly COVID-19 testing, regardless of vaccination status.