SACRAMENTO, Calif. (AP/CBS13) — Healthcare workers in California will be required to be fully vaccinated by September 30 as the state is losing ground in the battle against new infections of a more dangerous coronavirus variant.

The order, issued Thursday by the California Department of Public Health, is different than what Democratic Gov. Gavin Newsom said last month when he announced the state’s roughly 2.2 million health care workers would have the choice of either getting vaccinated or submitting to weekly testing.

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Now, the order does not give health care workers a choice. It says all must be fully vaccinated by the end of September, with exceptions for people who decline the vaccine because of a religious belief or workers who cannot be inoculated because of a qualifying medical reason backed up by a note signed by a licensed medical professional.

The labor union United Healthcare Workers West issued a statement applauding the decision.

“Governor Newsom’s decision today requiring healthcare workers to be vaccinated against COVID-19 recognizes the critical threat the Delta variant poses to the well-being of all Californians. Throughout the pandemic, SEIU-UHW’s number one priority has been to keep our healthcare workers, families, and patients safe. As such, we have consistently encouraged everyone to get the COVID-19 vaccine, which has been proven safe and effective to reduce severe illness from infection,” the statement read.

The change comes as California is seeing the fastest increase in new virus cases since the start of the pandemic, averaging 18.3 new cases per 100,000 people a day. Most of the state’s new infections are caused by the delta variant, a more contagious version of the coronavirus that the state says “may cause more severe illness.”

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“Increasing numbers of health care workers are among the new positive cases, despite vaccinations being prioritized for this group when vaccines initially became available,” said Dr. Tomás J. Aragón, California’s public health officer. “Recent outbreaks in health care settings have frequently been traced to unvaccinated staff members.”

The order represents a new hard line in public health leaders’ quest to convince the hesitant to receive the vaccine. Several states are focusing on health care workers, since they are around vulnerable patients.

But other states with similar requirements have carved out exceptions, like in Oregon, where health care workers can instead get regular COVID-19 testing. In Maryland, the vaccine mandate only applies to certain state employees, such as those who work in health care facilities under the state health department.

In California, vaccine mandates are perilous for Newsom, who is facing a recall election next month fueled in part by anger over his handling of the pandemic. Newsom has angered many parents by continuing to require masks indoors at all public schools, but he has not required all teachers and staff to be vaccinated.

California’s new vaccine mandate is broad and applies to workers in most health care facilities, including hospitals, skilled nursing facilities, psychiatric hospitals, adult day health care centers, dialysis centers, hospice facilities and clinics and doctor’s offices.

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In a separate order, the state required hospitals, skilled nursing facilities and intermediate care facilities to verify all visitors have either been vaccinated or tested negative for COVID-19 at least three days before an indoor visit. The state said it would give its updated guidance for long-term care facilities “in the near future.”