The director of the National Institute for Allergies and Infectious Diseases Anthony Fauci speaks during the daily briefing in the Brady Briefing Room of the White House in Washington on January 21, 2021.

Almond Ngan | AFP | Getty Images

The Biden administration is taking the emergence of a new strain of coronavirus in New York “very seriously,” said White House chief medical officer Dr. Anthony Fauci, on Monday.

The new strain, which researchers call B.1.526, is spreading rapidly in New York and carries a mutation that, according to The New York Times, could make vaccines less effective. The variant first appeared in November and now makes up about 1: 4 virus sequences, the Times reports.

Fauci said Monday the strain likely came from Washington Heights, a neighborhood in the uppermost part of Manhattan, before it spread to other boroughs. He said US officials must “keep an eye on” the strain, including the possibility that it could evade protection from antibody treatments and vaccines.

“We take the New York variant 526 very seriously,” said Fauci during a press conference at the White House.

US health officials are increasingly concerned that the emergence of new, highly contagious varieties could reverse the downward trend in infections in the US and delay the nation’s recovery from the pandemic. They are also urging Americans to get vaccinated as soon as possible before potentially new and even more dangerous variants continue to take hold.

At the same press conference, the head of the Centers for Disease Control and Prevention Dr. Rochelle Walensky said she was “really concerned” that some states are rolling back public health measures to contain the pandemic, as US cases appear to be weakening at a “very high” rate of 70,000 cases per day.

“Seventy thousand cases a day seem good compared to what we were a few months ago,” she said. “Please listen to me clearly: at this level of cases with expanding variation, we are completely losing the hard-earned ground we have gained.”

In addition to the B.1.526 strain in New York, officials monitor four other variants. As of Sunday, the CDC had identified 2,400 cases of variant B.1.1.7, which were first identified in the UK. The agency identified 53 cases of the B.1.351 strain from South Africa and 10 cases of P.1, a variant for the first time in Brazil. California scientists are also monitoring a variant called B.1.427 / B.1.429.

Fauci said Monday that there are many “unknowns” about the New York variant, but officials are “looking very carefully” at the strain.