Invoking the kind of restrictions on activities that marked the early months of the pandemic, Sonoma County starting Wednesday will prohibit large gatherings — indoors and out — in an effort to tamp down the alarming spread of COVID-19 from the super-contagious omicron variant.

For now, health officials in other Bay Area counties say they have no plans to follow suit, even though their virus transmission rates are in many cases worse than Sonoma County’s. But more restrictions elsewhere aren’t completely off the table.

“There’s so much rapid change. Numbers are going up rapidly,” Santa Clara County Executive Jeff Smith said. “I wouldn’t be surprised if something came up in the next week or so.”

Sonoma County’s order begins at 12:01 a.m. Wednesday and will remain in effect until Feb. 11. It prohibits gatherings of 50 or more people indoors and 100 or more outdoors, as well as gatherings of 12 or more people considered high risk for severe COVID-19 illness.

It doesn’t apply to regular school instruction or outdoor recess, attendance at work, courthouses, places of worship, cafeterias, shopping malls, stores, restaurants and museums.

But it applies to any other public or private event that brings people together in a single room or space, including at an auditorium, gymnasium, stadium, arena, large conference room, meeting hall or wedding venue, regardless of whether they include assigned seating with entry restricted by tickets and gates. Events already planned during the period of the order must be postponed or canceled.

Like every Bay Area county, Sonoma is experiencing its highest COVID-19 case rate ever, with a 7-day daily average topping 165 cases per 100,000 people. By comparison, the county saw a rate of 58 per 100,000 during last winter’s peak.

But the picture is even worse in other Bay Area counties: The 7-day average case rate is more than 180 per 100,000 in Santa Clara, Alameda and San Francisco counties, and higher still in Los Angeles, the state’s largest city, where Los Angeles County now reports the state’s highest rate of 285 per 100,000 people. Statewide, the current case rate of 198 shatters last winter’s peak of 112. About 100,000 new infections were reported every day this past week, driving California’s total cases past 6 million on Tuesday. Less than three weeks ago, the state topped 5 million.

In making its decision to limit public gatherings, Sonoma County Health Officer Dr. Sundari R. Mase said the county’s case rate has risen nearly 400% in two weeks “and is predicted to continue to rise.” Mase said the percentage of positive tests for the virus “is higher than at any point in the pandemic,” and hospitalizations have more than doubled. Half of the cases in the last two weeks with known sources of infection were linked to gatherings, most involving more than 12 people, she said.

“Without mitigation efforts, state modeling projections show the current surge has the potential to lead to more than three times that number of individuals hospitalized with COVID-19, which would overwhelm local hospital bed and staffing capacity,” Mase said.

Health officials in San Francisco, Marin, Contra Costa, Alameda, San Mateo and Santa Cruz counties all said Tuesday they aren’t planning any return to gathering restrictions.

“Given how widespread COVID-19 is, a similar order would be disruptive and would not significantly impact the trajectory of the pandemic in Alameda County at this time,” Alameda County Health Officer Dr. Nicholas Moss said.

San Francisco Health Officer Dr. Susan Philip cited the city’s high vaccination rates and the relatively low incidence of severe disease seen among the vaccinated as justification to hold off on new restrictions for now.

“Of course, we will follow the data, around hospitalizations in particular,” Philips said, urging people to “take extra caution,” wear high-quality face masks. “Our intention is not to impose additional restrictions.”

Sonoma County’s new rule was already disrupting events Tuesday. The Cinnabar Theater announced that it will be streaming its current production of Cyrano Jan. 21-23, and the opening of Amy and the Orphans has been pushed back from Feb. 4 to Feb. 11, with streaming remaining an option to its live performances.

“While we are sorry that we must do this, we are looking forward to getting past this current surge,” Cinnabar Theater Executive Director Diane Dragone said.

The Luther Burbank Center for the Arts in Santa Rosa said it will postpone, reschedule or cancel 10 large-scale events that were scheduled through Feb. 11, affecting 5,400 ticket holders. The events included a production of the game show The Price is Right and a performance by Grammy nominated artist Beth Hart. The Bodega Chamber of Commerce also announced cancelation of its Chowder Day scheduled for Jan. 28.

For Sonoma’s renowned wine industry, the order’s silver lining is that it is coming in the off-season, before tastings and weddings kick into high gear.

“From my perspective and for our overall impact, it’s better for us to have less activity now so when we hit the spring, we’ll be able to be fully open,” said Nick Caston, general manager of Harvest Moon Estate and Winery in Santa Rosa.

But that doesn’t mean it’s painless, said Henry Belmonte, owner of VJB Vineyard and Cellars, Wellington Cellars and Kenwood Farms and Ranch.

“It creates situations that become incredibly frustrating for individuals who’ve already booked an event,” he said. “For many business owners and for our guests, it’s the back-and-forth, one step forward and three steps back.”

Staff Writers Jason Green, Aldo Toledo, Annie Sciacca, Shomik Mukherjee, Harriet Rowan and Jackie Burrell contributed to this report.