Coronavirus updates: 84% of California population to go on lockdown Sunday night

Nearly 329,000 people could die from COVID-19 by Dec. 26, the Centers for Disease Control and Prevention said Thursday. 

The agency's latest national ensemble forecast predicts that the number of newly reported COVID-19 deaths will likely increase over the next four weeks, with 9,500 to 19,500 new deaths likely to be reported in the week ending Dec. 26. 

The national ensemble predicts that 303,000 to 329,000 total COVID-19 deaths will be reported by this date. The U.S. death toll currently stands at 275,550, according to Johns Hopkins University.

On Wednesday, CDC Director Robert Redfield warned that as many as 472,000 people might die from the virus by February.

-ABC News' Anne Flaherty

A new stay-at-home advisory in Delaware will ban residents from gathering indoors with anyone not in their household, reported ABC Philadelphia station WPVI.

The order will last from Dec. 14 to Jan. 11.

Gov. John Carney also announced a new mask mandate requiring masks whenever indoors with someone from outside the household.

The first vaccine doses have arrived in the United Kingdom after being transported on freezer trucks from the production facility in Belgium, British authorities confirmed to ABC News. The doses are on their way to distribution centers, which will then dole them out to be administered according to the priority list.

The U.K. Department of Health and Social Care announced Wednesday that a vaccine developed by Pfizer and BioNTech has been approved for use in the U.K.

Vaccinations for some high-priority people could begin next week. The majority of U.K. vaccinations will take place next year.

-ABC News' Angus Hines

California Gov. Gavin Newsom said he's "pulling the emergency break" and asking residents to not gather with people outside of their household.

In regions where the ICU capacity is below 15%, a stay-at-home order will go into effect for three weeks, Newsom said.

ABC Los Angeles station KABC reports that latest projections show all of the state's regions except the Bay Area falling below 15% in the next few days.

In those regions, bars, hair salons and personal care services will close, he said.

"If we don't act now our hospital system will be overwhelmed... we'll continue to see a death rate climb," Newsom said.