It's been detected in at least 40 countries.
There are 11 confirmed cases in California with two in Santa Clara County, where officials there say little is known about the new variant.
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Doctor George Han is the county's Deputy Health Officer and Infectious Disease and Response Branch Director.
"Early indications say that it probably behaves just like the BA-1 omicron lineage, but again it's probably too early to tell, because of the small number of cases that have occurred so far," Dr. Han said.
Officials aren't releasing any information about the two people who tested positive for this sub-variant.
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Concerns over BA.2 come as coronavirus cases continue to decline in the U.S. and the Bay Area, with hospital admissions going down as well.
Federal data shows an eight-percent drop in COVID-19 hospitalizations in the across the country over the last week.
California's seven-day positivity rate has dropped. It's at 19.6-percent, which is down 1.7-percent from a week ago.
But officials warn to stay vigilant amid this unpredictable pandemic.