By Dustin Manduffie

(CN) — California will once again require both vaccinated and unvaccinated to wear masks in indoor settings starting Dec. 15 through at least Jan. 15.

The omicron variant prompted the new mask mandate, a COVID strain first identified in November which is now working its way across the nation. As of Dec. 10, 18 cases of the new strain had been reported across the state.

“Wearing a mask is going to be one of the most important things to help us get through this period of uncertainty,” said state health secretary Dr. Mark Ghaly said during a press conference Monday afternoon.

Individuals attending events with more than 1,000 people will be required to show proof of a negative COVID-19 test prior to entry into the venue — one day before for antigen tests and two days for PCR tests. The state also recommends travelers coming to the state be tested three to five days before their arrival. California maintains its existing recommendation that anyone attending an outdoor event with more than 10,000 people should be tested, but hasn’t mandated that as of yet.

Ghaly said the state is taking these precautions to prevent the need for another unpopular business shutdown of the kind that residents experienced earlier in the pandemic. He also noted that while some counties are doing far better than others in regards to their case and vaccination rates, the new rules will apply equally to everyone across the state.

“The idea around enforcement and compliance is important and what we hope to see is that a large number of people and counties say ‘Hey, we can do this for a month, it’s only a month,’ so that we’re better off in the end,” Ghaly said. “We know that if people do implement this it will have a real impact on case transmission and help protect our hospital system and save lives.”

This is a developing story.