“Two cases of BA.2, a subvariant of omicron, were detected earlier this month in Washington,” a spokesperson for the Washington Department of Health told Fox News Digital on Monday.
The spokesperson said that health officials do not have much information on the new subvariant, which has been reported in parts of Europe and Asia.
United Kingdom health authorities declared BA.2 a “variant under investigation” on Friday, saying that “there is still uncertainty around the significance of the changes to the viral genome.”
Viruses mutate as they spread through a population, with some mutations impacting vaccine effectiveness, as well as the lethality and transmissibility of variants, according to the CDC.
The World Health Organization said Monday that BA.2 differs from the original omicron strain on the spike protein, emphasizing that the two subvariants should be studied independently to determine “immune escape properties and virulence.”
Two cases of BA.2 have also been detected in Houston, where Dr. Hana El Sahly dubbed it “stealth omicron” since it is harder to pick up on a PCR test, according to WOAI.
Omicron, which was first detected in South Africa in late November, has rapidly spread throughout the world and is now responsible for 99.5% of all new cases in the United States, according to CDC data.
The 7-day average for new cases throughout the United States was at 686,715 on Saturday, down from an all-time high of 789,960 on Jan. 15.