New Omicron subvariants BQ.1 and BQ.1.1 accounted for over 35 per cent of Covid-19 cases in the US this week, according to the latest estimates from the US Centers for Disease Control and Prevention (CDC).
BQ.1.1 made up nearly 19 per cent of circulating variants and BQ.1 was estimated to make up 16.5 per cent of circulating cases this week, Xinhua news agency reported, citing a report released by the CDC on Friday.
The two new variants have been growing especially fast since October. At the beginning of October, each one accounted for about 1 per cent of new infections in the US, but they have been roughly doubling in prevalence each week.
The two variants accounted for about one in four new Covid-19 infections nationwide last week, CDC data showed.
The two variants are descendants of Omicron's BA.5 subvariant and have been spreading rapidly in Europe.