The U.S. recorded more than 486,000 new COVID-19 cases in a day, marking the third straight day of record numbers, according to data released by the U.S. Centers for Disease Control and Prevention.

The new data comes as states are going through their huge backlogs of tests taken during the Christmas weekend.

In the last week, the U.S. has reported more than 2.2 million new cases, which averages out to about 220 Americans testing positive for COVID-19 every minute.

The CDC will not be providing new data updates until Jan. 3, due to the New Year's holiday.

-ABC News' Arielle Mitropoulos

Officials from Michigan's Department of Health and Human Services sent a letter to schools across the state urging them to either postpone large gatherings or make them virtual.

"Large gatherings (involving 100 or more people) should be held using remote technology or postponed, if not essential. Large gatherings would include events with large numbers of people from multiple households such as conferences or meetings, sporting events, and concerts," the letter read.

The state also urged schools to require masks for everyone who enters school buildings and to test students regularly.

-ABC News' Will McDuffie

More than 90,000 Americans are currently hospitalized with COVID-19, which is double the number since November, according to a memo from the U.S. Department of Health and Human Services.

On average, more than 9,400 Americans are being admitted to the hospital with COVID-19 every day, a 20% increase compared to the last week, HHS said.

The hospitalization numbers are still roughly three-quarters of the same period in 2020, the data showed.

-ABC News' Arielle Mitropoulos and Josh Margolin

Mondli Gungubele, the South Africa's Minister in the Presidency, tweeted some promising updates on the country's current COVID-19 surge.

The country's health department saw a 29.7% decrease in the number of new cases detected in the week ending Dec. 25 compared to the previous week.

"All indicators suggest the country may have passed the peak of the fourth wave at a national level," the minister tweeted.

South Africa was one of the first nations to record the omicron COVID-19 variant and saw cases spike in late November.

The health department said that while the omicron variant is highly transmissible, the country's hospitalization rates were lower than in previous waves.

South African officials announced they will lift several restrictions, including its curfew and crowd limits for indoor and outdoor activities.

-ABC News' Christine Theodorou

Last week, the CDC reported that omicron had overtaken delta to become the dominant COVID-19 variant in the U.S. However, on Tuesday, the CDC revised its initial estimates to noticeably lower numbers of omicron cases.

Last Monday, the CDC said omicron was estimated to makeup more than 73.2% of new cases as of Dec. 18. Now, the CDC says just 22.5% of new U.S. cases were estimated to be omicron as of Dec. 18. 

According to new data from this week, the CDC says omicron is now estimated to account for 58.6% of all new cases, officially making it the dominant strain in the U.S. In the New York and New Jersey region as well as the deep South, omicron is estimated to account for more than 85% of new cases. 

A CDC spokeswoman said in a statement, "There was a wide predictive interval posted in last week’s chart, in part because of the speed at which omicron was increasing. We had more data come in from that timeframe and there was a reduced proportion of omicron. It’s important to note that we’re still seeing steady increase in the proportion of omicron."

ABC contributor Dr. John Brownstein, an epidemiologist at Boston Children's Hospital, said, "It may be possible that a large portion of their [the CDC's] sequencing data had come from labs that were specifically looking for s-gene samples, thus falsely elevating the percent omicron in samples."

-ABC News' Arielle Mitropoulos