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 27, 2021, 2:21 AM 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 22, 2021, 1:58 PM EST

Omicron confirmed in all 50 states

Omicron cases have now been reported in all 50 states, according to an ABC News count.

The South Dakota Department of Health announced Wednesday that officials detected omicron in a young man in his 20s, making South Dakota the final state to confirm the highly transmissible variant.

The CDC on Monday said omicron was estimated to be the dominant variant in the U.S., representing more than 73% of new cases as of Dec. 18.

People wait on line to get vaccinated for COVID-19, Dec. 21, 2021, in New York.
Brittainy Newman/AP

The CDC warned this week that models, which estimate the trajectory of coronavirus in the U.S., suggest that the number of new omicron infections will likely surge in the weeks to come and could exceed previous peaks.

-ABC News' Arielle Mitropoulos, Darren Reynolds

Dec 22, 2021, 12:45 PM EST

Pfizer COVID treatment pill authorized by FDA

Pfizer's at-home pill treatment for COVID-19 was authorized by the FDA on Wednesday.

Pfizer's Covid-19 antiviral pills being manufactured in a laboratory in Freiburg, Germany. The Paxlovid pill has been shown to cut hospitalization or death by nearly 90 percent among newly-infected, high risk patients.
Pfizer via AFP/Getty Images

When taken early, Pfizer's pill was 89% effective at reducing the risk of severe illness and death from COVID-19, according to the company.

It's also effective against omicron, Pfizer said.

-ABC News' Cheyenne Haslett

Dec 22, 2021, 12:31 PM EST

Biden again tests negative after staff exposure

President Joe Biden received another PCR test Wednesday and again tested negative following exposure to a staff member who recently tested positive for COVID-19, the White House said.

President Joe Biden answers questions after speaking about the status of the country's fight against Covid-19 and the Omicron variant, in the State Dining Room of the White House in Washington, D.C., Dec. 21, 2021.
Brendan Smialowski/AFP via Getty Images

Biden was near the staff member for about 30 minutes on Air Force One on Friday, during a trip to Philadelphia from South Carolina, according to White House press secretary Jen Psaki.

The staff member, who is fully vaccinated and boosted, tested negative Friday morning but tested positive Monday, according to the White House.

The president first received an antigen test Sunday and a PCR test Monday and both came back negative, Psaki said.

-ABC News' Sarah Kolinovsky

Dec 22, 2021, 12:00 PM EST

Delta says omicron surge may 'create significant disruptions,' asks CDC to shorten isolation period for the fully vaccinated

Delta Air Lines said the omicron surge "may exacerbate shortages and create significant disruptions."

Delta is urging the CDC to shorten the time fully vaccinated people must isolate following breakthrough infections, saying the current 10-day period "may significantly impact [its] workforce and operations."

Delta proposed a five-day isolation from symptom onset for those who experience a breakthrough infection. 

"Our employees represent an essential workforce to enable Americans who need to travel domestically and internationally," Delta said in a letter. 

Ninety percent of Delta's workforce is fully vaccinated.

-ABC News' Amanda Maile