COVID-19 live updates: City sees fourfold increase in pediatric hospitalizations

The shift reflects the spread of the omicron variant.

ByEmily Shapiro, Ivan Pereira, Meredith Deliso, and Mary Kekatos
Last Updated: December 25, 2021, 4:55 PM EST

As the COVID-19 pandemic has swept the globe, more than 5.3 million people have died from the disease worldwide, including over 816,000 Americans, according to real-time data compiled by Johns Hopkins University's Center for Systems Science and Engineering.

About 61.7% of the population in the United States is fully vaccinated against COVID-19, according to data from the Centers for Disease Control and Prevention.

Latest headlines:

Here's how the news is developing. All times Eastern.
Dec 25, 2021, 4:55 PM EST

American, Delta, JetBlue, United report impacts from omicron

Four of the five major U.S. airlines are reporting impacts from omicron.

Passengers line up at John F. Kennedy International Airport after airlines announced numerous flights were canceled during the spread of the Omicron coronavirus variant on Christmas Eve in Queens, New York, Dec. 24, 2021.
Dieu-nalio Chery/Reuters

Holiday travelers pass through Salt Lake City International Airport, Dec. 24, 2021, in Salt Lake City.
Rick Bowmer/AP

American Airlines said Saturday that it canceled some Christmas Day flights due to "a number of COVID-related sick calls."

Delta said Friday that omicron and weather contributed to cancellations. Up to 200 of 3,004 Christmas Day flights may be canceled, Delta said.

JetBlue also reported "a number of" canceled flights due to sick calls from omicron.

"Additional flight cancellations and other delays remain a possibility as we see more Omicron community spread," JetBlue said.

United also said some flights were canceled because of omicron.

-ABC News' Mina Kaji

Dec 25, 2021, 1:57 PM EST

France, Italy see new record highs

France recorded 104,611 new COVID-19 cases in the last 24 hours, setting a new record high, according to the national public health agency Santé Publique France. Saturday's number is 10,487 cases higher than the tally from Friday, marking the largest daily increase in infections since the start of the pandemic.

Italy recorded 54,762 new cases in the last 24 hours. a new historic record since the start of the pandemic.

-ABC News' Ibtissem Guenfoud

Dec 25, 2021, 1:28 PM EST

Cases soar in Florida

Florida's COVID-19 positivity rate has soared to 13.8% this week, up from 5.3% the week prior, according to state data. One week before that, the positivity rate was just 2.6%.

Florida hit a record high of 31,758 daily cases on Thursday, surpassing the previous record set in August, according to ABC Miami affiliate WPLG.

This comes as the nation sees an increased demand for testing for the holidays.

Dec 25, 2021, 1:03 PM EST

USC to begin semester remotely

When the University of Southern California's spring semester begins on Jan. 10, classes will be remote for the first week due to the spread of omicron, university officials said Friday.

In-person classes are set to start Jan. 18.

Students must show a negative test before attending in-person class, and all faculty, staff and students are required to get the booster shot, officials said.