Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, testifies on the federal response to the coronavirus on Capitol Hill during a Senate Committee hearing on Health, Education, Labor and Pensions March 18 in Washington, DC . Susan Walsh / Pool / Getty Images

The United States is now sequencing 10,000 to 14,000 coronavirus samples every week looking for cases of new variants across the country, said Dr. Rochelle Walensky, director of the US Centers for Disease Control and Prevention, on Thursday.

However, more sequencing is needed to keep track of the spread of new variants, Walensky said in a hearing for the Senate Committee on Health, Education, Labor and Pensions.

“We’re doing somewhere between 10,000 and 14,000 sequences a week now,” Walensky said. “Right now we really want to be in the 25,000 range.”

The US does far less genome sequencing than other countries like the UK, and the CDC said that means there is no clear picture of how variants are distributed. The CDC has forecast that the more contagious variant B.1.1.7 will be the dominant version of the virus in the US by the end of March.

What the CDC needs: Walensky said the agency needed the money allocated in the American Rescue Plan to improve sequencing capabilities. “The additional $ 1.75 billion is indeed essential to fund the jurisdiction for the next genome sequencing capacity,” she said. “Not all jurisdictions have this capacity, and we really need to be able to expand it across the country.”

Equipment is also needed to sequence samples and trained personnel is essential, Walensky said. “We need to develop a workforce so people understand how to do genomic epidemiology,” she said. “This is not a standard application. That’s not what people normally know and that’s why we need to develop this workforce. “