The highly contagious variant, first identified in the UK, is likely to account for up to 30% of Covid-19 infections in the US, said White House chief medical officer Dr. Anthony Fauci, on Friday.

The variant, named B.1.1.7, has been reported in at least 94 countries and discovered in 50 US jurisdictions, Fauci said during a White House press conference about the pandemic, adding that the numbers are likely to rise.

The UK first identified strain B.1.1.7 last fall, which appears to be spreading more easily and faster than other variants. It has since spread around the world, including the United States, Fauci said. US researchers had identified 5,567 cases through genetic sequencing by Thursday, according to the Centers for Disease Control and Prevention. US health officials say the variant could become the dominant strain in the US by the end of this month or early April.

New variants are particularly a problem for public health officials as they could become more resistant to antibody treatments and vaccines. High-level health officials, including Fauci, have urged Americans to get vaccinated as soon as possible. They say that if the virus cannot infect hosts and cannot replicate, the virus cannot mutate.

Public health officials and Americans can counter the variant by doing two things, Fauci said. “Get as many people to be vaccinated as quickly and as quickly as possible with a vaccine that we know will work against this variant and, ultimately, to implement the public health measures we have been talking about all this time have … masking, physical distancing and avoidance of congregational attitudes, especially indoors. “

A study recently published in the British Medical Journal found the variant was associated with a 64% higher risk of dying from Covid-19 than previous strains. Researchers from the University of Exeter and the University of Bristol analyzed data from more than 100,000 patients in the UK between October 1 and January 28.

“We’re in a position right now where we have a plateau of around 53,000 cases a day,” said Fauci. “The concern is that there are a number of states, cities, and regions across the country that are withdrawing some of the mitigation methods we talked about: withdrawing mask mandates, withdrawing from essentially non-public health interventions.”

Fauci’s comments on B.1.1.7 come a day after he argued over masks at a hearing with Republican Senator Rand Paul.

Paul claimed people shouldn’t wear masks after vaccination as the chance of getting Covid-19 is “practically 0%”. “Isn’t it just theater?” The Kentucky junior senator, an ophthalmologist, asked during a hearing on the Senate Committee on Health, Education, Labor, and Pensions.

In response, Fauci said the emergence of new, highly contagious variants poses a threat to people with antibodies. “I can only say that masks are no theater,” said Fauci. “I totally disagree with you.”