A subvariant of the highly contagious omicron variant of COVID-19 has become more prevalent in Santa Clara County in recent weeks, but the county's top health official said Thursday it does not seem to be spurring a broader increase in cases of the virus.
The BA.2 variant of omicron has driven a recent surge in cases in the United Kingdom, growing roughly 80 percent faster than the original omicron variant that drove the United States' winter surge.
Santa Clara County Health Officer Dr. Sara Cody said that the variant has been detected in northern parts of the county via wastewater testing, but local COVID-19 data has remained flat or in decline.
"It spreads even more easily than omicron and we are seeing quite a bit of it," Cody said Thursday. "It's increasing in prevalence across the country and in California, particularly the Bay Area."
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Cody said she was unsure why the subvariant hasn't stalled the virus' decline in Santa Clara County, but said local health officials plan to monitor its prevalence closely in the coming weeks.
In a statement on the subvariant released last month, officials with the World Health Organization said that while BA.2 may be more transmissible than the main omicron variant, the gap between the two is not as wide as the difference in virulence between omicron and the delta variant.
"Further, although BA.2 sequences are increasing in proportion relative to other Omicron sublineages, there is still a reported decline in overall cases globally," the WHO said.
Research is ongoing regarding how potent the subvariant is or the risk of reinfection it may present.
Cody argued that regardless of when the next surge in cases presents itself, the county is highly unlikely to return to past methods of reining in the virus like implementing stay-at-home orders.
"When we issued our shelter-in-place order two years ago, we had very few, if any, tools," she said. "We didn't know a lot about how the virus behaved, so there's a lot of information we were missing. Masks were hard to come by, we had very few tests and, very importantly, we had no vaccine."
Cody argued that county residents have done an admirable job protecting themselves from the virus, as Santa Clara County has one of the highest vaccination rates of any large county in the U.S., with more than 90 percent of eligible residents completing their initial vaccine series.
She added that the county's public health measures have likely saved more than 2,000 lives locally based on Santa Clara County's COVID death rate compared to that of the state and the country at large.
"The future remains a little bit uncertain," Cody said. "I think we've gotten a bit accustomed to that. But at the same time, I do feel optimistic ... because of how our community has pulled together collectively, and I see that carrying forward."