(Reuters) – California will require healthcare workers and workers in “high-risk congregate settings” to get a COVID-19 vaccine booster by Feb. 1, Governor Gavin Newsom said on Wednesday, as part of the state’s response to the highly transmissible Omicron variant.

The mandate follows a Sept. 30 mandate for the state’s healthcare workers to be fully vaccinated. Workers have been able to request an exemption for religious or medical reasons.

State employees who still have not received a booster must undergo testing for COVID-19 twice each week until Feb. 1, Newsom said in a statement.

Newsom, who disclosed the new mandate in a statement, was due to elaborate on the new requirement at a press conference later on Wednesday.

While California, the country’s most populous state, exceeds the national average for full vaccinations with 65.5%, it slightly lags the national average in booster shots at just under 30%, according to the Center for Disease Control and Prevention.

The governor also announced that all public school students, from Kindergarten to 12th grade, will receive a rapid COVID-19 test as they head back to school from winter break.

The state also will expand operating hours for state-operated testing centers that have reached capacity, Newsom added.

(Reporting by Brendan O’Brien in Chicago and Peter Szekely in New York)