California will become the first state to mandate COVID-19 vaccinations for school teachers and staff, Politico reports. Gov. Gavin Newsom is set to announce the mandate Wednesday at a press conference at a Bay Area school. Teachers and staff will have to show their schools proof of vaccination or face weekly COVID-19 testing. All students in the state are required to wear masks in accordance with Centers for Disease Control and Prevention guidance. The California Teachers Association and the California Federation of Teachers, the state’s two largest teachers unions, support Newsom’s decision, according to the outlet.

The news comes as schools grow increasingly worried over the Delta variant, with five California school districts—including San Francisco—already imposing their own mandates. It is also a major shift for Newsom, who is facing a recall election next month. Newsom has not imposed a mask or vaccine mandate across the state, even as local counties institute their own regulations. On Tuesday, the state had 14,919 COVID-19 cases and 68 deaths, with 62.6 percent of the state at least partially vaccinated, per the Los Angeles Times.