The U.S. recorded 2,760 coronavirus deaths on Wednesday, the highest daily death toll since the onset of the pandemic.

The toll surpassed the previous high set in April, several weeks after much of the U.S. shut down businesses in response to coronavirus spread. The number of patients hospitalized with coronavirus passed 100,000 on Wednesday, more than double the highest level set in spring.

“The reality is, December and January and February are going to be rough times,” Centers for Disease Control and Prevention head Robert Redfield told Congress on Wednesday morning, before the latest data was recorded. “I actually believe they’re going to be the most difficult time in the public health history of this nation.”

Redfield added, “The mortality concerns are real, and I do think, unfortunately, before we see February, we could be close to 450,000 Americans” dead from coronavirus.

Over 14 million Americans have tested positive for coronavirus since the start of the pandemic, about four percent of the country’s population. Of those who have tested positive, two percent—275,000 patients—have died. The latest outbreak is spread across rural areas of the country.

The Food and Drug Administration is on track to grant emergency authorization to the Pfizer-BioNTech coronavirus vaccine later this month. Moncef Slaoui, the co-head of the Trump administration’s vaccine development program Operation Warp Speed, said on Wednesday that supplies of vaccines from Pfizer and Moderna could allow for significant inoculations over the next few months.

By February “we will have potentially immunized 100 million people, which is really more or less the size of the significant at-risk population: the elderly, the healthcare workers, the first-line workers, people with comorbidities,” Slaoui said at a press conference.