(CNN/CBS13) — Gov. Gavin Newsom is expected to announce on Wednesday that California teachers and other school employees must either be vaccinated against COVID-19 or submit to regular testing.

Under a new order that Newsom will unveil, California will become the first state in the nation to implement such a requirement, which will be effective in mid-October, sources told CNN.

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The health order will closely mirror a similar mandate issued earlier that all California health care workers become vaccinated.

The mandate was first reported by Politico on Tuesday night.

School districts Sacramento as well as San Francisco, Oakland, and Long Beach have already implemented such a measure. The state’s largest school district, Los Angeles Unified, has required weekly Covid testing, but stopped short of mandating educators be vaccinated.

“We’re getting all our kids safely back in in-person instruction,” Newsom said Friday in an event touting mental health resources. “We want to do it in a safe way where these kids can get that full support.”

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Most districts and unions have been very supportive of the health order, according to sources.

CNN has reached out to the California Teachers Union, which represents educators across the state.

“Those that are unvaccinated need to get vaccinated. That way we can keep our kids, without any stress or anxiety, back in person throughout the school year,” Newsom said Friday.

California is home to more than 1,000 school districts employing more than 300,000 teachers, with about 6.1 million students.

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