Based on our most recent estimates from CDC surveillance, the B.1.1.7 variant is now the most common lineage circulating in the United States," Rochelle Walensky said at a White House press briefing on Wednesday.
"The virus still has hold on us, infecting people and putting them in harm's way and we need to remain vigilant," she added. "We need to continue to accelerate our vaccination efforts and take the individual responsibility to get vaccinated when we can."
The B.1.1.7 variant, which was first found in the British region of Kent, has raised concerns among the experts because it could undermine the protection given by vaccines.
Studies have suggested that the UK variant is more contagious than the original strain, is possibly more dangerous and associated with a higher risk of death.
Meanwhile, Michael Osterholm, a member of the White House COVID-19 advisory board, announced on Tuesday that vaccinations cannot necessarily provide complete protection.
He added that the different variants of the virus are creating a “new pandemic” and a “fourth wave” of surging COVID-19 cases.
“In terms of the United States, we’re just at the beginning of this surge. We haven’t even really begun to see it yet,” Osterholm, who is also the director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said.
As of Wednesday, 30.9 million people in the US have contracted the virus while over 556 thousand have succumbed to it since the outbreak last year.