The country’s first confirmed case of the omicron coronavirus variant has been detected in San Francisco, public health officials announced Wednesday.
Dr. Grant Colfax, San Francisco’s Director of Public Health, said at a Dec. 1 press conference that the patient was a traveler who returned from South Africa on Nov. 22 and developed symptoms soon after. Colfax said that the individual—who is fully vaccinated with the Moderna vaccine—is experiencing mild symptoms and is self-quarantining. They have not received a booster shot.
So far, contact tracers have determined that no close contacts with the individual have been infected.
“This is cause for concern, but it is certainly not a cause for us to panic,” Colfax said, adding that no changes to current health orders or new restrictions on activities are planned at this point. “We are prepared here in the city for this.”
In a press conference Wednesday at a COVID-19 vaccination clinic in Merced County, Gov. Gavin Newsom said he doesn’t foresee any school closures due to the omicron variant—so long as “California continues its nation-leading efforts” with respect to vaccinations.
Since the World Health Organization classified omicron as “a variant of concern” on Nov. 26, public health officials have maintained that it would only be a matter of time before a case was detected in the United States. The variant is now South Africa’s dominant strain, but early reports from doctors in the country indicate symptoms have been largely mild.
The delta variant remains the dominant strain of the virus in the U.S. making up more than 99% of current cases.
According to the WHO, omicron has an unusually high number of mutations that could potentially impact its ability to spread or cause serious disease. Several of the variant’s mutations impact the virus’ spike protein, which current vaccines target.
“There’s still a lot we do not know about omicron,” Colfax said. “We don’t know how infectious it is, although there’s a strong likelihood it is more infectious than delta. We don’t know how sick it will make people, but that is being studied furiously right now across the world, and we don't know yet how fully effective the vaccines are for protecting against transmission or serious cases of illness and hospitalization.”
During a White House press briefing Wednesday, the country’s leading infectious disease expert Dr. Anthony Fauci said the detection of the variant underscores the importance of both vaccination and booster shots as a protective measure against COVID-19.
“Our experience with variants such as the delta variant is that even though the vaccine isn't specifically targeted to the delta variant, when you get a high enough level of an immune response, you get spillover protection even against a variant that the vaccine wasn't specifically directed at,” Fauci said. He added that current vaccines are also likely to provide protection against the worst symptoms of an omicron infection.
Fauci emphasized that people who are eligible for a booster shot should receive one as soon as possible, a message echoed by local public health officials. Around 175,000 San Francisco residents have received their booster shots since they were authorized in September.
“Our message is the same as yesterday,” Colfax said. “To best protect against this variant, get vaccinated for goodness sake, get your booster if you’re eligible, continue to wear those masks inside where required, continue to take the steps we know have been successful in San Francisco to prevent major loss of life and slow the spread of the virus.”