The United States has recorded 2.2 million confirmed COVID-19 cases over the last week, setting a grim record as the highest number of cases confirmed in one week.

The previous record was set just a few days earlier from Dec. 22 to Dec. 29, when the U.S. confirmed 1.9 million COVID-19 cases. Before that, the previous record totaled 1.75 million cases from Jan. 5 to Jan. 11 at the start of 2021.

At least 10 of the 13 school districts in Hudson County, New Jersey are switching back to remote learning next week as the daily total of confirmed COVID-19 cases skyrocket in the state.

Bayonne, Jersey City, Harrison, Union City, West New York, Weehawken, Guttenberg, Hoboken, East Newark and North Bergen will go remote until Jan. 7 at the earliest.

On Thursday, New Jersey reported a record number of 27,975 positive daily tests. The previous record was 20,483, which was confirmed just one day earlier.

The Food and Drug Administration is likely to authorize Pfizer COVID-19 booster shots for 12- to 15-year-olds next week, a source with direct knowledge of the plan told ABC News.

An authorization may come as early as Monday.

-ABC News' Eric Strauss

More COVID-19-positive children in the United States are being hospitalized each day than at any other point in the pandemic, according to newly updated federal data.

On average, just under 380 children with COVID-19 were admitted into the hospital daily between Dec. 22 and Dec. 28, according to data from the Centers for Disease Control and Prevention.

The country's pediatric COVID-19 hospital admission rate has nearly tripled in the past month, CDC data shows.

Nationwide, nearly 2,900 children are currently hospitalized with confirmed or suspected cases of COVID-19 -- approximately 1,300 more patients than a month ago -- according to data from the Department of Health and Human Services.

Less than a third of eligible children -- ages 5 to 17 -- in the U.S. are currently fully vaccinated against COVID-19.

Three new studies released Thursday by the CDC found COVID-19 vaccines to be safe and effective for children.

-ABC News' Arielle Mitropoulos

Dr. Anthony Fauci strongly recommended against large New Year's Eve parties at Wednesday's White House briefing.

"Should you change or cancel your plans? If your plans are to go to a 40-50 person New Year's Eve party with all the bells and whistles and everybody hugging and kissing and wishing each other a happy new year, I would strongly recommend that this year, we do not do that," Fauci said.

Fauci said "all indications point to a lesser severity of omicron versus delta." But he warned, "we should not become complacent since our hospital system could still be stressed in certain areas."

White House COVID-19 coordinator Jeff Zients said, "We have directly helped more than 30 states and territories by deploying over 2,100 federal personnel and thousands of ambulances, ventilators and other critical supplies."

Supplies include gloves, masks, respirators and face shields, he said.

He added, "More than 13,000 National Guard members have been activated in 48 states to support the COVID response, from vaccinations, to testing, to clinical care."

At the briefing, CDC Director Rochelle Walensky defended the agency's shortened isolation guidelines.

"We do know the vast majority of viral transmission happens in those first five days, somewhere in the 85 to 90% range. So if a person can isolate for the first five days they absolutely should," she said. "We also don't know that antigen tests give a good indication of transmissibility at this stage of infection. On the other hand, we know that after five days people are much less likely to transmit the virus and that masking further reduces that risk. And this is why people need to mask for five days after the five days of isolation."

After five days, asymptomatic people with COVID-19 can leave isolation, but must wear masks around others, according to the new guidelines.

-ABC News' Cheyenne Haslett