The U.S. government is buying 600,000 more doses of sotrovimab, the only the monoclonal antibody treatment expected to hold up against omicron, according to the drug makers, GlaxoSmithKline and Vir Biotechnology.

These doses are set to be delivered to the government over the next two months, the drug makers said.

This brings total sotrovimab doses purchased by the federal government to approximately 1 million.

Short supply of sotrovimab has been a growing concern for the White House as omicron spreads.

Until recently the government had not invested in buying bulk stock of sotrovimab, as it has with other monoclonal treatments. The government spent billions buying Regeneron and Eli Lilly's products to ensure there would be enough supply, but both of those may not hold up against omicron.

-ABC News' Sasha Pezenik

Florida reported 126,704 new COVID-19 cases this weekend, ABC Miami affiliate WPLG reported, citing CDC data.

Orlando opened a new testing site Monday at Camping World Stadium.

About 3,000 United Airlines workers currently have COVID-19, though none are in the hospital, the airline said.

On one recent day, one-third of all United Airlines employees at Newark Airport called in sick, the airline said.

United CEO Scott Kirby said the airline is cutting its near-term flight schedule to ensure they have enough staffing.

Kirby added that, prior to the vaccine requirement, United had one employee die each week from COVID-19.

-ABC News' Sam Sweeney

Some 20 million people across three Chinese cities are now under lockdown due to COVID-19 outbreaks.

Anyang, home to 5.5 million people, was the latest city to lock down its residents after discovering two cases of the fast-spreading omicron variant. Another 13 million people are under lock down in Xi'ian and 1.1 million in Yuzhou, with both cities still battling the highly contagious delta variant. Neither has reported any cases of omicron.

Meanwhile, restrictions have been imposed in the port city of Tianjin, about 80 miles southeast of Beijing, which is to host the 2022 Winter Olympics next month. The city's 14 million people are being tested for COVID-19 after two locally transmitted cases of omicron were detected over the weekend -- the first for mainland China.

-ABC News' Karson Yiu

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