COVID-19 hospitalizations in California and the Bay Area have reached their highest point since February, when the region was still coming out of the winter omicron surge.
As of Friday, there were 4,009 people hospitalized with COVID-19 statewide, with Bay Area hospitals reporting 770 patients, according to data from the California Department of Public Health.
COVID admissions to Bay Area intensive care units also climbed to 94, compared with 63 a month ago. The region accounts for about a quarter of 419 ICU patients across the state.
Infections remain high across California as the test-positive rate nears record levels. The state is averaging 40 new daily coronavirus cases per 100,000 residents, with 16.7% of tests coming back positive for the virus. The Bay Area is reporting 43 daily cases per 100,000 residents, a figure that has remained largely unchanged for more than a month.
But cases are probably significantly underreported because of so many people now testing at home — the results of which are not usually recorded with the state or counties — or not testing at all.
With highly infectious and immune-evasive BA.4 and BA.5 sublineages of omicron now the dominant strains in Northern California, the region is on the brink of its second-largest wave of COVID-19 cases since the start of the pandemic.
Hospitalization and ICU figures, however, remain well below those logged during earlier COVID surges when fewer people were vaccinated and treatments such as antiviral medications weren’t yet available. Deaths from COVID, a lagging indicator of pandemic trends, continue to remain low across California. About 40 people are now dying per day, compared with 25 a month ago — still below the levels recorded last fall and winter.
Indeed, numerous preliminary studies suggest that BA.4 and BA.5 are not more virulent than earlier versions of the coronavirus. Rising hospital admissions are a function of the swelling case load, but the rate of hospitalization is far lower than it was even during the original omicron surge last winter, not to mention for earlier variants.
The new variants have mutated substantially from their omicron ancestor, to the point that some scientists believe that BA.5, at least, should be given its own Greek letter name. That genetic drift may partly explain why infection with the original omicron provides little protection against reinfection with its variants.
“The main reason this variant has become the predominant one that is now circulating is that it is able to evade previous immunity,” said Dean Blumberg, chief of pediatric infectious diseases at UC Davis Children’s Hospital. “Even people who have partial immunity from a previous infection or vaccination can still have a breakthrough infection.”
For the second consecutive week, all Bay Area counties are classified as having high COVID-19 levels, according to federal data. The Centers for Disease Control and Prevention uses metrics based on new coronavirus cases and hospitalizations per 100,000 residents, plus the percent of inpatient beds occupied by COVID-19 patients, to classify COVID levels.
At that level, health care systems may be under stress due to high patient loads, and all residents are advised to wear masks in indoor public spaces.
“The good news is that the vast majority of breakthrough infections now are outpatient illnesses,” Blumberg said. “They are not resulting in the kind of severe illness that we saw earlier in the pandemic when no one had immunity, which led to increased hospitalizations and deaths.”
Aidin Vaziri is a San Francisco Chronicle staff writer. Email: avaziri@sfchronicle.com
