More than 300 children with COVID-19 are in Ohio hospitals, including Dayton Children's Hospital, where workers are seeing a significant increase in pediatric COVID-19-related hospitalizations.

Dr. Vipul Patel, chief of pediatric intensive care at Dayton Children's, told ABC News the ICU is now busier than at any other point in the pandemic.

COVID-19 is only exacerbating previously existing health issues for many children, Patel explained, adding that many parents are shocked to see their children become so sick, and some families have even expressed regret for not vaccinating their kids. Nationwide, about 35% of eligible children (ages 5 to 17) are fully vaccinated, according to federal data.

Dayton Children's respiratory therapist Hillary O’Neil said it's been particularly difficult to see children who are too young to understand what is happening sick and scared.

“You can see it in the faces of kids that can’t talk -- their eyes get really big and they, we watch them struggle to breathe,” O’Neil said. “Then on top of that we watch their parents struggle to watch their child, and that is sometimes just as hard as watching the kids.”

Jackie Kerby, whose baby, Enaeshya, is hospitalized with COVID-19, told ABC News, "She’s getting these fevers in the night, and they’re not coming down. … I am terribly scared."

Across the U.S. more than 5,000 children are currently hospitalized with a confirmed or suspected case of COVID-19, according to federal data. On average, hospital admissions among children have quadrupled over the last month.

-ABC News' Arielle Mitropoulos, Kayna Whitworth

New York state's COVID-19 cases are falling after experiencing a major surge over the holidays, according to state data.

New York recorded 60,374 new cases in the last 24 hours -- an improvement from New Year's Day when 85,476 daily cases were reporting during a spike in testing demands.

The Supreme Court has issued a stay of the vaccine-or-test requirement imposed on private businesses with at least 100 employees by the Occupational Safety and Health Administration.

In a 6-3 ruling, with the three liberal justices dissenting, the court finds likelihood the challengers will prevail and that OSHA exceeds its authority.

At the same time, the justices voted 5-4 to allow the Biden administration to require health care workers at facilities that treat Medicare and Medicaid patients to be vaccinated, subject to religious or medical exemptions.

-ABC News' Devin Dwyer

About 8,000 of Delta Air Lines' 75,000 employees had COVID-19 over the last four weeks, Delta CEO Ed Bastian told CNBC.

"Good news is that they were all fine. There's been no significant issues," he said.

"But it's knocked them out of the operation" amid the busiest travel season in two years, he said.

United CEO Scott Kirby said Tuesday that around 3,000 of United workers have COVID-19 right now.

Across the U.S., 3,783 TSA employees are currently at home with COVID-19, the agency said.

-ABC News' Mina Kaji, Sam Sweeney

British Prime Minister Boris Johnson apologized Wednesday for attending a party during England's strict lockdown in 2020.

It was the first time that Johnson acknowledged he went to a garden party at his official residence and office on London's Downing Street in May 2020. He is facing growing anger and calls for his resignation over claims he and his staff flouted COVID-19 restrictions by holding a "bring your own booze" party. At the time, Johnson's government had imposed restrictions barring people in England from meeting more than one individual outside their household.

During the weekly Prime Minister’s Questions session in the House of Commons in London on Wednesday, Johnson said he had considered the garden party to be a work event to thank his staff for their efforts during the pandemic.

"I want to apologize," Johnson told lawmakers. "With hindsight, I should have sent everyone back inside."

The prime minister urged people to await "the full conclusion" of an investigation by senior civil servant Sue Gray into several alleged parties by government staff. Gray will report her findings by the end of the month.

Opposition Labour Party leader Keir Starmer said Johnson's defense was "the pathetic spectacle of a man who has run out of road" and demanded he "do the decent thing and resign."

The prime minister declined to resign and didn't explicitly admit that he had broken any rules, but said he understood "the rage."

"I know that millions of people across this country have made extraordinary sacrifices over the past 18 months," he added. "I understand the anger, the rage that they feel at the thought that people in Downing Street were not following those rules."

-ABC News' Guy Davies, Ian Pannell and Joseph Simonetti