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Time to wear a mask again? Here’s what Bay Area health experts say amid rising COVID cases

San Fransisco Chronicle

For each of the past two years, Thanksgiving heralded the onset of a COVID-19 surge. A third pandemic winter finds the U.S. with more tools to combat the coronavirus — an updated booster, ample at-home tests, a helpful antiviral drug — and many prior restrictions erased as people return to public and social settings.

That might leave some wondering how to navigate a period in the pandemic where precautions are largely up to the individual. As the holidays arrive and COVID numbers show signs of climbing again — albeit not to previous surge levels so far — what are currently the best practices to stay healthy? How much caution is needed?

“I think it’s become much more of an individual judgment call,” said Dr. Bob Wachter, chief of medicine at UCSF. “So I rarely tell people what they should do, other than things that make no sense to me not to do, like for example getting a booster if you haven’t gotten one in over six months.”

Instead, Wachter said he’ll often share with people strategies he and his family are following. His include being up to date on COVID-19 vaccines and wearing a KN95 mask in crowded indoor settings, he said. He isn’t dining indoors at restaurants right now, and his 12-person Thanksgiving gathering took place mostly outside with attendees taking rapid antigen tests beforehand.

“That to me is a reasonably prudent, moderately careful way of living life that is not all that burdensome,” Wachter said. “But I certainly know perfectly reasonable people who are doing less than that and just have decided they are willing to take the risk.”

People’s practices should take into consideration their own health status as well as that of people they live or interact with often, experts said. Elderly adults and people who are immunocompromised or have underlying medical conditions are at higher risk for severe outcomes from the virus.

“I would be recommending continuing masking for people at high risk,” said Dr. Warner Greene, senior researcher at the Gladstone Institutes. For everyone, following local coronavirus trends could help to inform decisions, he said.

“If your community is in the midst of a huge surge, you’d want to be more defensive,” Greene said. “If you’re in a low virus area, you can probably get away with less intervention. That said, anytime you’re in a crowded place, particularly indoors, you’re putting yourself at risk, even if the viral load in the region is low.”

In California, mask mandates were lifted months ago for all but a few settings. Health officials, though, continue to cite wearing a mask indoors in public, staying home if sick, testing for symptoms and good ventilation among steps to take to guard against the virus.

Stanford infectious disease specialist Dr. Abraar Karan said he sees sense in masking, “even if you can’t do it all the time, in high-risk settings and at times where there is more community transmission.” He defined “high-risk” as crowded indoor spaces, like grocery stores, or settings where you might not be able to distance from a person with symptoms.

“I’ve seen some arguments from folks who’ve said, ‘What’s the point of wearing a mask with COVID? It’s so transmissible that if you don’t get infected now, you’ll get infected later,’” Karan said.

“I don’t think that makes sense. We don’t use that logic to stop washing our hands or cleaning our food. What you’re doing is reducing the risk that you get sick, and I think that’s a very reasonable thing to do.”

Health experts have voiced cautious optimism that any U.S. winter surge won’t be as bad as the last two. True, newer omicron subvariants in circulation appear to be more immune-evasive.But waves of BQ.1.1 cases in New York and XBB cases in Singapore have not led to major increases in hospitalizations.

California is certainly seeing its metrics climb. On Thursday, the state reported 3,793 patients with confirmed COVID-19 in hospitals, up 133% from a month before. That included 654 patients in Bay Area hospitals, with this week marking the first time since August that the number had topped 600.

The state also reported a 10.8% test positivity rate, more than doubling in a month, and its rate of 13.6 new daily cases per 100,000 residents was up from 6.1 a month earlier. Infection brings risk of developing long COVID. And the rise comes amid surges in flu and RSV already testing pediatric hospitals in regions including the Bay Area.

“We are seeing significant increases right now across the Bay Area in all three of those viruses,” said Dr. Matt Willis, the Marin County health officer. “Each is slightly different in terms of the measures that we might take to protect ourselves, but they do all have one tool in common, and that is face-covering.”

Willis said Marin County as of Tuesday had almost as many patients hospitalized for flu as for COVID-19. “We are recommending that people, especially if you’re at a high risk for a bad outcome if infected, take that measure to cover their face with a high-quality mask in an indoor public setting,” he said.

If gathering with family or friends, particularly those at risk for severe illness, Willis suggested wearing a mask “vigilantly” for four or five days before to “help ensure you’re not infectious during that gathering.” He also suggested all attendees take a rapid antigen test before such gatherings.

“I think it’s super-clear that we need, for our own mental health and well-being and relationships, to be gathering together over the holidays,” Willis said. “So this is really about making sure we can be with our loved ones as safely as possible.”

California’s public health department does require masking, regardless of one’s vaccination status, in health care settings, in long-term care and adult and senior care settings, for 10 days after confirmed exposure to the virus, and at businesses or locations that require them. Otherwise, guidance is based upon COVID-19 Community Levels reported by the U.S. Centers for Disease Control and Prevention.

As of Thursday, Alameda, Contra Costa, San Francisco and San Mateo counties were at the “low” level, where CDPH guidance says masking is up to personal preference and people at higher risk should consider masking in crowded indoor public places. Marin and Santa Clara counties were at the “medium” level, where the guidance suggests that everyone consider wearing a mask in indoor public places.

Los Angeles County was also in “medium” tier. Health officials there resumed “strongly recommending” masking indoors in public recently, citing rising COVID rates. But health officer Dr. Barbara Ferrer cautioned Thursday that the county could return to mandatory indoor masking if case and hospitalization metrics enter the “high” level — which could occur as soon as next week.

A well-fitting N95 or KN95 mask can be a “very powerful public health tool” to combat transmission of respiratory virus, said Dr. John Swartzberg, a UC Berkeley infectious disease expert who also acknowledged that mask messaging is likely to meet with fatigue nearly three years into the pandemic.

A different question amid colder months may be whether to dine indoors at a restaurant. Swartzberg said the decision should weigh both a “personal calculus” of one’s own risk factors (age, health) and a “public health calculus” including, for example, not doing so if one has respiratory virus symptoms.

“I think most people would predict we are going to see an increase in cases” this winter, Swartzberg said. “The question that all of us have is how much of a rise? And (there’s) no way of answering that.”


San Francisco Chronicle staff writer Aidin Vaziri contributed to this report.

Matt Kawahara is a San Francisco Chronicle staff writer. Email: Twitter: @matthewkawahara

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