You likely know several people infected with COVID-19 if you live in the San Francisco Bay Area, which has seen an explosion of cases since early April.
“Everyone and their grandmother has COVID,” said UCSF infectious disease expert Dr. Peter Chin-Hong, on the surge in the Bay Area.
The good news is that despite the skyrocketing cases, hospital admissions have yet to experience the same alarmingly dramatic spike seen in some of the past surges, such as the Delta variant.
“We continue to closely monitor hospitalizations,” wrote Alison Hawkes, communications director for the San Francisco Department of Public Health, in an email. “Similar to the Omicron surge in January, this current increase in cases does not appear to be a serious illness in vaccinated and boosted individuals. However, we expect hospital admissions to increase as case numbers rise. At the moment this is not the case. It seems that we are running the risk of running out of hospital capacity.”
Chin-Hong said UCSF’s four hospitals, which treat patients from across the region, are a good indicator of the state of the pandemic across the Bay Area.
“Hospitalizations have been really flat since around March 11,” he said. “We’ve stayed like that since then. It hasn’t really gone up.”
Chin-Hong said that in previous spikes, hospital admissions generally picked up two weeks after cases emerged, and that this time it hasn’t.
As of May 23, there were a total of 22 patients with COVID in the four hospitals. Some patients may be hospitalized for COVID, while others were admitted for other reasons and happened to test positive, Chin-Hong said. At the peak of the last spike on Jan. 20, there were 152 patients at UCSF.
Chin-Hong believes high rate of booster shots among seniors protects Bay Area from serious diseases; Some areas of the country with lower booster rates are seeing significant increases in hospital admissions.
“If you look at the refresher rates in San Francisco, we’re really high, especially in the over-65 age group, like double that of other parts of the US,” Ching-Hong said. “San Francisco has one of the best booster rates compared to the rest of the county.”
dr George Rutherford reiterated that Bay Area hospitalization numbers show the vaccine is still working.
“The vaccine does what it was designed to do, and what it does well, is prevent serious illness and death,” Rutherford said. “Hospitalizations are a manifestation of that.”
Here are some answers to other questions you may have about the state of the SF Bay Area pandemic.
How widespread is the virus in the SF Bay Area?
Official county data shows an increase in cases, but the numbers are higher than official counts because more people are testing at home with rapid antigen tests. If someone tests positive at home, it usually doesn’t register with the county.
Chin-Hong said the UCSF’s asymptomatic test positivity rate — the percentage of people tested in the hospital who have no symptoms and end up testing positive — is a better indicator of the prevalence of the virus in the community. It is currently at 6.4%.
“That means if you go to 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 as of early March was 1.5%.
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, closer to 50% in the SF Bay Area . The remaining cases are likely to be BA.2, which is also spreading slightly.
“BA.2.12.1 is considered to be 25% more transmissible than BA.2, which is itself 30 to 80% more transmissible than BA.1, which in turn is 200% more transmissible than Delta,” said Chin-Hong.
According to the CDC, early research indicates that BA.2.12.1 and BA.2 do not cause more serious diseases than previous variants.
What’s next for the SF Bay Area?
UCSF infectious disease expert Dr. Monica Gandhi said we could look at the UK to predict what will happen this summer as the trajectory of the pandemic in the US has often lagged behind the UK by a few weeks
In the UK, cases increased significantly 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 in the UK increased during their BA.2 and subvariant surge, hospitalizations, intensive care unit admissions and deaths remained relatively low compared to previous increases in cases, presumably reflecting the high immunity of the population in the region,” Dr Gandhi wrote in an email. “With the US lagging behind the UK by about four weeks, hopefully our spike in cases will ease by the end of the month.
“With nearly 60% of US adults and 75% of children ages 0 to 17 exposed to the virus, according to an April 26, 2022 CDC seroprevalence study,” she added, “with 82.5% of our population are over 5 years old Having received at least one dose of the vaccine, and with a trajectory likely to follow that of the UK, I think COVID-19 cases, hospitalizations and deaths will hopefully remain low this summer will.
