Cases of a highly transmissible Omicron subvariant were doubling in the US each week over the past month, according to the data updated on Tuesday by the country’s Centers for Disease Control and Prevention (CDC).
The variant, BA.2, was responsible for 11.6 per cent of coronavirus infections in the country in the week ending March 5, Xinhua news agency reported, citing the CDC estimates.
The variant accounted for only 1 per cent of new cases in the week ending February 5, rising to 2.2 per cent in the week ending February 12, 3.8 per cent in the week ending February 19, and 6.6 per cent in the week ending February 26, CDC data showed.
New lab and animal experiments suggested that BA.2 may be capable of causing more severe disease than the original Omicron strain.