Tyler Levene helps Brenda Hammond train at Red Dot Fitness Gym, in San Jose, Calif., on June 15, 2021. (Harika Maddala/Bay City News)

Though California has again mandated masks in indoor public settings, the state has granted exemptions to some Bay Area municipalities for gyms and other businesses already requiring all patrons to be totally vaccinated.

Contra Costa, Marin, San Francisco, Alameda, and Sonoma counties said their rules won’t change, despite the monthlong statewide mandate that went into effect Wednesday morning.

The previous mandate was lifted June 15. But rising case numbers statewide and the looming threat of the new Omicron variant prompted the state to again require masks in most public places, at least until Jan. 15.

“The limited exceptions we made are for very low-risk scenarios where everyone is vaccinated,” Dr. Chris Farnitano, health officer for Contra Costa County, said in a statement. “Our community already understands and is following these rules and it would be confusing to change them for just one month.”

Those scenarios include office settings, commuter vehicles, religious gatherings, and college classes where certain criteria are met. Those present must be fully vaccinated, there should be no more than 100 people present, the site shouldn’t be open to the general public, and the host or organization must have a list of people present.

The host must also provide visible signage prohibiting entry to those with COVID-19 symptoms, and no one present should have symptoms or have been exposed to someone with COVID-19 for the past 14 days.

Since Thanksgiving, the seven-day average case rate in California has increased 47 percent, and hospitalizations have gone up 14 percent. State officials say holidays bring more risk, with more people traveling and staying indoors.

“Given the current hospital census, which is at or over capacity, even a moderate surge in cases and hospitalizations could materially impact California’s health care delivery system within certain regions of the state,” says the state’s new guidance, issued Monday. “Other states and countries with similar vaccination rates that have relaxed masking requirements are seeing surges in COVID-19 cases and increasing stress in their health care systems.”

Though early research suggests the severity of the Omicron variant may be milder than the current dominant Delta strain, researchers also say it spreads easier.

For more information on COVID-19 in California, people can go to https://covid19.ca.gov/.