The U.S. logged its highest single-day total of new Covid-19 cases on Tuesday, with 441,278 infections surpassing the previous daily record by close to 150,000.
The Centers for Disease Control and Prevention’s tally represents a grim new milestone in the coronavirus pandemic and comes as the Omicron strain has quickly taken hold throughout the U.S., leading to long lines at testing sites and sold-out rapid tests at many stores.
It also comes after the Christmas holiday shuttered testing sites and may have contributed to testing backlogs.
A CDC spokesperson said that the daily case total is likely an "overestimate" due to lagging state reporting.
"The counts of cases will become more stable after the new year," CDC spokesperson Jasmine Reed told POLITICO.
Officials logged more than 291,000 new cases Dec. 20, nearly eclipsing the previous record of 294,015 set last winter, before vaccines were widely available. The U.S. averaged 240,408 new cases per day over the past week, well more than double the rate in early December.
The CDC revised its estimate for Omicron’s prevalence earlier Tuesday, sharply cutting a previous estimate that the variant accounted for 73.2 percent of cases nationwide on Dec. 18 to 22.5 percent.
The agency's latest modeling estimates Omicron made up about 58.6 percent of U.S. cases as of Dec. 25.
The surge comes as many Americans gather with loved ones for the holidays, with data from the Transportation Security Administration showing air travel at levels close to pre-pandemic 2019 figures.
The rising caseload has prompted the Biden administration to roll out a plan to help curb the variant, includes delivering 500 free million in-home rapid tests to Americans after previously declining to make tests free.
The administration has urged Americans to get vaccinated and boosted and also plans on establishing FEMA surge facilities and vaccination sites while preparing to send protective equipment and troops and medical workers to overburdened hospitals.
It is not yet clear how Omicron’s severity compares to previous variants, including Delta, though officials have been optimistic that it may be less severe. But some public health officials fear Omicron’s surge is again straining the nation’s health care system.