SAN FRANCISCO — With the Omicron surge fading fast and people clamoring for a return to pre-pandemic life, public health officials in California and beyond are facing new pressure to relax mask and vaccine safety rules.But many remain wary of declaring victory, aware that new variants are possible in the months ahead. Hopes for a definitive end to the pandemic have been dashed many times, they say, and it would be unwise to drop both masking and vaccine requirements when such uncertainty remains.Instead, health officials are urging smaller steps.“This phase of the pandemic is nearing its end. I think that’s clear,” UC San Francisco epidemiologist Dr. George Rutherford said at a campus meeting last week. “What variants emerge after that is really pretty much anyone’s guess. … There’s just no predicting them, unfortunately.”Some California counties are beginning to repeal vaccination mandates to enter certain businesses. Contra Costa County on Friday said it was lifting its vaccine-or-test requirement for customers of indoor restaurants, bars and gyms.Health officials in the Bay Area’s third-most-populous county said the relaxation of the mandate, which has been in place since August, comes now that 80% of residents are fully vaccinated, and 2 in 5 residents have received a booster shot. By contrast, in Los Angeles County, 69% of residents are fully vaccinated, and 1 in 3 residents have received a booster.“We believe now is the right time to loosen a requirement that made a lot of sense last summer, when a different variant of COVID-19 was dominant and there was less community immunity,” Dr. Ori Tzvieli, Contra Costa County’s acting health officer, said in a statement. “But by no means are we back to normal,” Tzvieli said. “There are still many more cases of COVID-19 in our community now than there were in mid-December, so we need to continue to take precautions when we go out.”But other parts of the Bay Area are still enforcing their vaccination rules. Oakland became the latest city in California to require proof of full vaccination to enter certain businesses after an emergency ordinance approved days before Christmas went into effect Tuesday. A similar rule is in place in West Hollywood and Berkeley.San Francisco, however, has tweaked some of its requirements. The city partially softened its vaccination verification rule Tuesday to allow indoor restaurants, bars, clubs, theaters and entertainment venues to permit unvaccinated customers to enter if they cite religious beliefs or a qualifying medical reason. But those people must show a recent negative coronavirus test — administered by a test provider and showing the person’s name — to enter.For vaccinated San Francisco customers, booster shots will now be required for entrance to certain locales for those who are eligible. San Jose made a similar adjustment Friday for indoor events of 50 or more people at city-owned sites, including the convention center and SAP Center, an indoor arena that’s home to the San Jose Sharks. San Francisco also eased its COVID-19 mask order for vaccinated gym members and office workers, allowing them to shed face coverings as long as they are up to date on their vaccinations and booster shots, if eligible.The Bay Area has been spared from the worst of the Omicron surge likely because of higher vaccination and booster rates and greater compliance with mask-wearing. Since New Year’s Day, there have been 42 COVID-19 deaths in Contra Costa County, about four deaths for every 100,000 residents. L.A. County’s death rate is four times worse — with 1,576 deaths since Jan. 1, or about 16 deaths for every 100,000 residents. L.A. County is also challenged by a higher poverty rate and overcrowded housing, which have always made it more vulnerable during the pandemic than the Bay Area. Among the 25 biggest metropolitan areas in America, L.A. has the highest percentage of overcrowded homes, according to 2019 data from the U.S. Census Bureau. Among all L.A. homes, 11% are considered overcrowded, compared with about 6% in New York and the Bay Area.L.A. County Public Health Director Barbara Ferrer said there are still valid reasons behind the county order requiring vaccinations for customers of indoor bars, wineries, breweries, nightclubs and lounges, as well as the city ordinance mandating proof of full vaccination to enter indoor restaurants, shopping centers, movie theaters, hair and nail salons, coffee shops, gyms, museums, bowling alleys, performance venues and other spaces.“We still have a lot of cases here, and we have a lot of transmission. And anything we can do to really help us get to a lower level of transmission, I think, is appropriate,” Ferrer said.Unvaccinated people can still enter city businesses by voicing a religious exemption, but they need to show proof of a recent negative coronavirus test. Opponents are gathering signatures to either force the City Council to rescind the rules or put the issue on the ballot for voters to decide. L.A. County has outlined criteria by which it would drop mask requirements in certain outdoor settings once COVID-19 hospitalizations drop, and in which indoor mask rules would be loosened after further gains. Supervisor Kathryn Barger has advocated for lifting the mask order. “Individuals should be allowed to make an informed choice about whether to mask up or not,” Barger wrote. Supervisor Holly Mitchell, however, has supported the policy, noting it helps reduce rates of transmission.“COVID-19 transmissions, quite frankly, disproportionately impact the everyday workers who make up the backbone of this very local economy,” said Mitchell, whose district has many Black and Latino residents who have suffered far worse health outcomes during the pandemic. “They are disproportionately brown and Black workers who must go to their jobs every day and interact with people every day.” A new study by scientists at UC Berkeley and the California Department of Public Health further illustrated the effectiveness of masks in preventing coronavirus infection. Published by the U.S. Centers for Disease Control and Prevention, the study found that always wearing a mask in indoor settings resulted in being less likely to test positive for the coronavirus compared with those who didn’t routinely wear masks. People who wore N95 or KN95 masks in public indoor settings had 83% lower odds of testing positive; those who wore surgical masks had 66% lower odds; and those who wore cloth masks had 56% lower odds. A number of doctors speaking at a campus discussion at UC San Francisco called for caution about shedding masks too quickly and warned there’s still a lot of uncertainty about what variants might emerge. “March seems soon to me to take away masks. I think we need to see more time to understand what’s going to happen,” Dr. Sarah Doernberg, associate professor of infectious diseases at UC San Francisco, said. “It feels a little premature to take that away.”Rutherford, who is also a board-certified pediatrician, cautioned against removing mask mandates in classrooms and daycare centers too quickly. For children age 2 to 4, for whom there is no licensed vaccine, masks remain the best layer of protection, he said. An outbreak could cause a daycare center to close for perhaps 10 days. For elementary, middle and high school students, who have had a chance to be vaccinated and, in some cases, boosted, “as transmission drops, we can back away,” Rutherford said. But dropping masks too quickly and potentially seeing a rise in outbreaks could result in large numbers of students being sent home for many days, and “I think that that’s a much greater disrupter of education than having masks on,” he said. It’s also important to consider children who have underlying health issues and who could benefit from extended mask mandates. “There are lots of situations in which you might want to add an extra layer of protection. But I think, compared to keep sending everybody home every time there’s a case, masks are a much less intrusive kind of intervention,” Rutherford said.Low vaccination rates among children are also a concern, experts caution. In San Francisco, 73% of children 5 to 11 years old are vaccinated with at least one dose, but in L.A. County, only 32% of children in the same age group are.People will have to make personal decisions about whether to shed masks. With California’s mask order set to expire Feb. 15, counties that don’t have their own mask order — such as Orange, San Diego, Riverside and San Bernardino — are likely to see their mask mandates end unless the statewide mandate is extended.UC San Francisco infectious diseases expert Dr. Peter Chin-Hong said he likely would continue wearing a mask in the near future in crowded indoor settings, such as at Costco. He’s also conscious about the possibility that, having received his booster in October, that his antibodies will again wane to the point that he may be more vulnerable to a breakthrough infection, although he’s confident about being protected against severe illness.