Washington, Mar 20 (IANS): The US is likely to see a resurgence in Covid cases in coming weeks due to the BA.2 sub-variant of the Omicron strain.

According to data from the Centers for Disease Control and Prevention (CDC), BA.2 has been tripling in prevalence every two weeks, ABC news reported.

As of the week ending March 11, BA.2 accounted for 23.1 per cent of all Covid cases in the US compared to 7.1 per cent of all cases the week ending February 26, the CDC data showed.

This follows a rise in several European countries such as Finland, France, Germany, the Netherlands and the UK, and Asian countries such as Hong Kong, China, and South Korea.

Anthony Fauci, the US top infectious disease expert, said given the growing prevalence of BA.2, he expects cases will increase within the next month, the report said.

"I would expect that we might see an uptick in cases here in the US because, only a week or so ago, the CDC came out with their modification of the metrics for what would be recommended for masking indoors, and much of the country right now is in that zone, where masking indoors is not required," he told ABC affiliate KGTV.

Fauci added that he believes BA.2 will become the dominant variant in the country, surpassing the original omicron variant, the report said.

In the UK, 93,943 cases were recorded last week, according to Johns Hopkins University, more than double the 45,303 recorded two weeks earlier.

"Europe has been an important sign of what we can expect in the US," said John Brownstein, an epidemiologist at Boston Children's Hospital was quoted as saying.

"Rising infections, an increase in variant prevalence and a slow booster rollout is likely a sign of a surge. Whether it will be another wave or small bump, we don't know yet," he added.

Last month, the UK scrapped all Covid measures including masks, testing and surveillance.

Several European countries followed suit, as did the US, which eased masking guidance for 70 per cent of the country, including for schools, the report said.

Fauci said he is encouraged that BA.2 does not appear to cause more severe disease, but warned if the US experiences another Covid wave, Americans must be willing to readopt mitigation measures.