The mutation of COVID-19 first detected in the United Kingdom is now the most common strain among all United States coronavirus cases, the Centers for Disease Control and Prevention (CDC) Director Dr. Rochelle Walensky said on Wednesday.

What You Need To Know

  • The COVID-19 variant first detected in the United Kingdom is now the most common strain among all U.S. cases, the CDC Director said Wednesday

  • CDC Director Walensky said she's concerned about the rise in variants and the increased number of young people being hospitalized for COVID-19

  • The B.1.1.7 variant now accounts for more than one-third of the cases in Michigan, where case numbers are close to peaks last seen in November and December

  • The COVID-19 Response Team said they're monitoring the situation in Michigan, including with a CDC team on the ground

The B.1.1.7 variant — which studies suggest is about 50% more contagious than the strains of coronavirus first detected last year and potentially more deadly — now accounts for more than 1 in 4 cases of COVID-19 in the U.S., according to CDC data collected through mid-March.

On Wednesday, CDC Director Walensky expressed her concern about the spread of variants around the country and the increased number of younger adults admitted into the hospital with COVID-19. 

“These trends are pointing to two clear truths: One, the virus still has hold on us, affecting people and putting them in harm's way, and we need to remain vigilant,” she said. “And two, we need to continue to accelerate our vaccination efforts and to take the individual responsibility to get vaccinated when we can.”

Walensky said the CDC is continuing to increase its surveillance and genomic sequencing efforts to track the variants, which are contributing to the spread of the virus in states with high case counts.

The B.1.1.7 variant accounts for 39% of cases in Michigan, according to the CDC’s latest data, a state that is seeing case numbers close to the levels in November and December. The variant accounts for 35% of cases in Tennessee and 34.5% of cases in Florida, according to the CDC.

On Wednesday, members of the White House COVID-19 Response Team were asked in a briefing whether they had considered sending more vaccines to Michigan and about other plans to aid the state.

CDC Director Walesnky said her agency has a team on the ground working with state officials.

“We’re working with the state to try and encourage that areas that have increased amounts of outbreaks ... that the state is surging vaccine supply to those areas,” she said.

White House COVID-19 Adviser Andy Slavitt said they don’t plan to send extra vaccines to Michigan for now, but he said that “all options are on the table” and pointed to the federal vaccine supply in places like community health centers and pharmacies as part of the solution.

“I wouldn't want to give the impression that we are someone who's sitting back and managing this pandemic and the vaccination program according to some formula. It's not true in the least,” Slavitt said. “We are getting the amount of vaccines we think are needed for the population.”

Officials repeated their warnings on Wednesday about Americans remaining vigilant and continuing to follow CDC guidelines, especially in the face of spreading variants.

“What we really want to do is to scale up that vaccination ... so that we can be in a place where we have more vaccine out there and more vaccinations out there and really less disease circulating,” Dr. Walensky said. 

“65,000 cases — that’s 65,000 opportunities for mutations to occur, for more variants to spread,” she said, pointing to the still-high daily average of new COVID-19 cases.