California is seeing a surge in cases as BA.5, a rapidly spreading subvariant, takes root

Though new case reports have climbed in California, local officials have hesitated to reimpose mask mandates or limits on public indoor settings. Residents relaxed outdoors in Mission Dolores Park in San Francisco in June. Credit…Mike Kai Chen for The New York Times

New York Times, by Soumya Karlamangla, July 7, 2022

California is in the grip of its third-largest coronavirus surge of the pandemic, with roughly 19,000 new cases being reported here each day on average, according to a New York Times database. The true number of people falling sick is undoubtedly even higher, since most at-home test results aren’t included in official case counts.

Experts say the surge is being driven by the Omicron subvariant known as BA.5, which has rapidly become dominant in the United States and is especially good at infecting people even if they’ve been vaccinated, boosted and already had the virus.

“It’s highly immune-evasive, and that is why it’s causing trouble,” said Dr. Eric Topol, a professor of molecular medicine at Scripps Research in San Diego. “And it comes along in California at the same time that we basically have this delusion that the pandemic is over.”

As of the end of June, 39 of California’s 58 counties had high community levels of the virus, including the whole Bay Area and the San Joaquin Valley, according to the Centers for Disease Control and Prevention, while only two rural counties in the state had low levels.

Unlike earlier in the pandemic, officials across California are now reluctant to enact any new restrictions to head off the surge. Alameda County tried reinstating an indoor mask mandate last month but rescinded it three weeks later.

Experts predict that without tighter rules or behavioral changes, the hyper-transmissibility of BA.5 will lead to a continued surge in cases, and probably a modest increase in hospitalizations and deaths, said Dr. Robert Kim-Farley, an infectious disease expert at the University of California, Los Angeles, Fielding School of Public Health.

“There is a bit of déjà vu that is occurring as we begin having another surge,” he said. “I think we’ll continue to see increases for a while, but I don’t anticipate we’re going to see anywhere near the prior level of infections of the first Omicron wave.”

Being vaccinated and boosted continues to provide strong protection against severe illness and death, experts say, and death figures in California have remained relatively low in recent weeks. But even a mild infection carries risks, including the lingering health issues of “long Covid,” which experts predict will affect more than one in five adult Covid survivors in the United States.

Dr. Bob Wachter, chair of medicine at University of California, San Francisco, has written recently about how his wife’s lingering fatigue after a coronavirus infection intensified his desire to avoid catching the virus at all. With BA.5 spreading in the state, he said, now is not the time to be in indoor public spaces like restaurants without wearing a mask.

Dr. Wachter wrote on Twitter on Sunday that at his institution, surgery patients without Covid symptoms are swabbed for the virus as a precaution, and that lately about 6.5 percent of those patients have been testing positive, suggesting that roughly one in 16 people in the Bay Area who do not seem sick at all are infectious.

“If 1 in 16 people who feel fine actually has Covid, spend enough time maskless indoors & it’s near-certain that you’ll get it,” Dr. Wachter wrote.