The state of the COVID pandemic in the SF Bay Area

“Everybody and their grandmother has COVID,” UCSF infectious diseases expert Dr. Peter Chin-Hong said of the Bay Area surge.

The good news is that despite the skyrocketing cases, hospitalizations have yet to see the same alarmingly dramatic rise that occurred in some of the past surges, such as with the delta variant. 

“We continue to monitor hospitalizations closely,” Alison Hawkes, director of communications for the San Francisco Department of Public Health, wrote in an email. “Similar to the January Omicron surge, this current swell in cases is not appearing as severe illness among people who are vaccinated and boosted. However, we do expect to see an increase in hospitalization whenever case rates increase. At this time, it does not appear that we are at risk of running out of hospital capacity.”

Chin-Hong said that UCSF’s four hospitals, where patients from across the region seek care, is a good proxy for the state of the pandemic across the Bay Area.

“Hospitalizations have really been flat since around March 11,” he said. “We’ve stayed like that since that time. It hasn’t really gone up.”

Chin-Hong said that with past surges, hospitalizations generally went up two weeks after cases rose, and that has yet to happen this time. 

There are a total of 22 patients across the four hospitals with COVID as of May 23. Some patients may be in the hospital due to COVID, while others came in for other reasons and incidentally tested positive, Chin-Hong said. At the height of the last surge, on Jan. 20, there were 152 patients at UCSF.

Chin-Hong thinks that the high rate of booster shots among seniors is protecting the Bay Area from severe disease; some areas of the country with lower rates of booster vaccinations are experiencing significant rises in hospitalizations. 

“If you look at San Francisco booster rates, we are really high, especially in that over 65-year-old age group, like double in other parts of the U.S.,” Ching-Hong said. “San Francisco has one of the best booster rates compared to the rest of the county.”

Dr. George Rutherford echoed that the Bay Area’s hospitalization numbers show the vaccine is still working.

“The vaccine is doing what it is designed to do, and what it does well is prevent severe disease and mortality,” Rutherford said. “Hospitalizations are a manifestation of that.”

Here are some answers to other questions that you might have about the state of the pandemic in the SF Bay Area.

Just how widespread is the virus in the SF Bay Area?

Official county data shows a climb in cases, but the numbers are higher than the official counts, because more people are testing at home with rapid antigen tests. When someone tests positive at home, it’s typically not recorded with the county.

Chin-Hong said that UCSF’s asymptomatic test positivity rate — the percentage of people tested at the hospital who have no symptoms and end up testing positive — is a better indicator of the virus’ prevalence in the community. Right now, it stands at 6.4%.

“That means when you go into a crowded grocery store, about 1 in 18 or 1 in 20 people are walking around with COVID and they might not know it,” he said.

By comparison, UCSF’s asymptomatic test positivity rate was 1.5% in early March.

Which variant is circulating in the SF Bay Area?

The Centers for Disease Control and Prevention estimates that 37% of cases in California are the highly transmissive BA.2.12.1 variant, but Chin-Hong said the number is likely higher, and closer to 50% in the SF Bay Area. The remaining cases are likely BA.2, which also spreads easily.

“BA.2.12.1 is thought to be 25% more transmissible than BA.2, which is itself 30% to 80% more transmissible than BA.1, which is itself 200% more transmissible than delta,” Chin-Hong said.

The CDC has said early research indicates that BA.2.12.1 and BA.2 do not cause more serious disease than previous variants.

What’s next for the SF Bay Area?

UCSF infectious diseases expert Dr. Monica Gandhi said we can look at the United Kingdom to predict what will happen this summer, as the pandemic’s trajectory in the U.S. has often often followed a few weeks behind the U.K.

The U.K. saw cases rise considerably for about six weeks, driven by BA.2 and its subvariants (including BA.2.12.1), with declines reported in the last three weeks. 

“Although COVID-19 hospitalizations rose in the U.K. during their BA.2 and subvariant surge, hospitalizations, ICU admissions and deaths remained relatively low compared to previous surges in cases, thought to be a result of high population immunity in the region,” Dr. Gandhi wrote in an email. “With the U.S. about four weeks behind the U.K., our surge in cases will hopefully start coming down at the end of the month.

“With almost 60% of adults in the US and 75% of children 0-17 having been exposed to the virus, according to a CDC seroprevalence study on April 26, 2022,” she added, “with 82.5% of our population over 5 having received at least one dose of the vaccine; and with a trajectory that is likely to follow the UK’s, I think that COVID-19 cases, hospitalizations and deaths this summer will hopefully remain low.”