Two cases of the new omicron subvariant BA.2 detected in Santa Clara County are believed to be the first such cases in the Bay Area.
In California, there have been at least 11 confirmed BA.2 cases.
UCSF infectious disease specialist Dr. Peter Chin-Hong said while BA.2 may be harder to detect than the original omicron variant, there's no indication it's more of a threat.
"We don’t think that it’s causing more severe disease," he said. "In fact, the Danish government released some data showing that so far they're not seeing increased hospitalizations due to this variant versus regular omicron."
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Chin-Hong said people should think of BA.2 as a child of omicron wearing slightly different clothing, adding that vaccines still play a critical role.
"I'm very, very confident that the vaccines will still help prevent people infected with BA.2 from going to the hospital and having severe illness," he said.
The two cases of BA.2 in Santa Clara County were detected by genomic sequencing. The county would not say if the patients were hospitalized.
The UK Health Security Agency and the World Health Organization have labeled BA.2 a variant under investigation, which is one step below a variant of concern.
Some scientists have dubbed it the stealth omicron because it may be more difficult to identify in PCR tests.
Chin-Hong said people should expect to see even more variants in the future.
"As long as there is transmission, there’s going to be a new variant being created," he said. "In fact, every two weeks there is a new variant being created."