The British tribe is changing into the predominant tribe in elements of the US, in response to the CDC director

CDC director Dr. Rochelle Walensky speaks to the press after visiting the FEMA mass vaccination center at the Hynes Convention Center in Boston, Massachusetts on March 30, 2021.

Erin Clark | Pool | Getty Images

The highly contagious variant of coronavirus, first identified in the UK, is becoming the predominant strain in many regions of the United States, the head of the Centers for Disease Control and Prevention said on Wednesday.

The variant known as B.1.1.7 now accounts for 26% of the nationwide spread of Covid-19 cases, said CDC Director Dr. Rochelle Walensky reporters during a White House press conference on the pandemic. It’s the predominant variety in at least five regions, she added.

The UK identified B.1.1.7 last fall, which appears to be more deadly and spreads more easily than other strains. Since then, it has spread to other parts of the world, including the US, which on Tuesday identified 11,569 cases in 51 jurisdictions, according to the CDC.

Florida has the most confirmed cases of the new variant, according to a map from the CDC data, closely followed by Michigan, Wisconsin and California. Public health officials say they are working as soon as possible to identify more cases.

Walensky said on Wednesday that she expected further infections in the United States due to the portability of variant B.1.1.7. She urged the public to continue pandemic security measures such as hand washing, wearing masks and social distancing.

Walensky’s comments come two days after she issued a terrible warning to reporters. She said Monday that she feared the nation was facing “impending doom” as variants spread and daily Covid-19 cases rise again, threatening to send more people to the hospital.

“I’m going to pause here, I’m going to lose the script, and I’m going to think about the recurring feeling I have of impending doom,” Walensky said. “We can look forward to so much, so much promise and potential where we are and so much reason to hope, but right now I’m scared.”

According to the Johns Hopkins University, an average of more than 63,000 new Covid-19 cases per day have been reported in the U.S. That number is up 16% over a week.

The Chief Medical Officer of the White House, Dr. Anthony Fauci said Sunday that the recent surge in cases is not only being caused by new varieties of the virus, but that travel and the relaxation of business restrictions are also a factor in the increase in infections.

“This is a critical moment in our fight against the pandemic,” Walensky said on Wednesday. “We cannot afford to let go of our watch.”

– CNBC’s Nate Rattner contributed to this report.