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

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