Since San Francisco’s first case of the highly contagious omicron Covid-19 variant was detected on Dec. 1, covid has been making a comeback: Positive cases have more than tripled at the Mission’s Unidos En Salud test site this month.
Early research, meanwhile, shows that vaccines are shockingly less effective at protecting against symptoms from omicron, compared to the delta variant, although vaccination is still critical in reducing the chances of growing seriously ill and landing in a hospital.
Current data shows that people who received their second vaccine dose in the summer are now only five percent protected against symptomatic disease if infected with the omicron variant; “practically nothing,” said Dr. Diane Havlir during a presentation today of early research on the variant from UC Santa Cruz. Someone infected with the delta variant could still have about 43 percent protection from their waning vaccine doses, four to six months ago.
“What happens if we boost? It looks much better,” said Havlir, a professor of infectious diseases at UCSF and a research lead for Unidos En Salud. But, even with a booster, protection against omicron symptoms goes up to only 48 percent, meaning other measures, like social distancing and masking, are necessary to lower the risk of infection.
A booster dose is still highly effective at preventing hospitalization: For both the delta and omicron variants, boosted people are more than 90 percent protected from that outcome.
But San Francisco, which currently has an 80 percent total vaccination rate, according to the Department of Public Health, has been slow to get booster shots. This could render many unboosted individuals vulnerable to serious illness and prone to transmission to family and friends during the holidays.
As of Dec. 13, city data showed that only 29 percent of 16- to 34-year-olds, and 44 percent of 35- to 49-year-olds have gotten a booster.
Considering the high transmissibility of the omicron variant, these low booster rates are concerning.
“Omicron, this new variant, is the fastest spreading variant we have ever seen since the onset of the pandemic,” said Havlir. The omicron variant, which was first detected in South Africa in November, is now in at least 89 countries around the world.
The city saw its first three cases of the omicron variant spreading within the community last week. All of those infected were vaccinated but had not yet received a booster dose, Havlir said. On Thursday, the Latino Task Force Hub at 701 Alabama St. had 15 positive tests, the highest single-day number in several weeks, according to coordinator Valerie Tulier-Laiwa.
Last week, the positive test rate went up to nearly 5 percent at the Unidos En Salud testing site at 24th and Capp streets, after several weeks hovering around 2 percent. By Saturday, Dec. 18, positivity had shot past 7 percent.
Although it spreads more easily, it is still uncertain how the disease’s severity compares to past variants, Havlir said, despite reports that an omicron infection may present only mild symptoms.
Havlir said urgent action is needed at this point, particularly in changing the official definition of “fully vaccinated” to include a booster dose, and making testing materials more widely available for at-home use.
Residents may already be taking the new variant more seriously; in just one day last week over 150 vaccines were administered at the Alabama Street hub, which Tulier-Laiwa called “pretty amazing numbers.” And last week, the Unidos En Salud site administered over 1,500 vaccines, more than 1,100 of them boosters.
“This is not the time to give up,” Havlir said. “We might be tired, but we have to do everything we can do to protect the community and the health of the broader city over the next month.”
The Unidos En Salud vaccination site at 24th and Capp streets offers free testing and vaccines, and requires no proof of ID. Staff are bilingual. It will be open Monday and Tuesday, from 9 a.m. to 3:30 p.m. After Tuesday Dec. 21, this site will close for the holiday.
Testing and vaccines are also available at the Latino Task Force resource hub at 701 Alabama St. on Thursday, Dec. 23 and Dec. 30 from 10 a.m. to 3 p.m.
Sign up for a vaccine appointment or walk in during open hours.