COVID-19 updates: Elizabeth Warren tests positive

The senator says she's experiencing "mild symptoms."

ByMorgan Winsor, Emily Shapiro, Ivan Pereira, and Meredith Deliso
Last Updated: December 20, 2021, 12:51 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 806,000 Americans, according to real-time data compiled by Johns Hopkins University's Center for Systems Science and Engineering.

About 61.4% 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 17, 2021, 12:40 PM EST

White House: Unvaccinated are 'looking at a winter of severe illness and death'

White House COVID-19 response coordinator Jeff Zients warned Friday that the unvaccinated are "looking at a winter of severe illness and death -- for yourselves, your families and the hospitals you may soon overwhelm."

Army medical personel tends to a Covid-19 patient on a ventilator at Beaumont Hospital in Dearborn, Mich., Dec., 17, 2021.
Jeff Kowalsky/AFP via Getty Images

CDC director Rochelle Walensky said she expects omicron to become the dominant variant in the coming weeks.

Asked whether the CDC will change its guidance on vaccinated people quarantining after exposure, which they currently don't have to, Walensky said, "We are actively following the science in that area, with regard to how the viral burden is both among vaccinated people and unvaccinated people, and the natural history of that viral burden with regard to isolation."

"And as that science emerges, we will update our evidence if need be," she said.

-ABC News' Cheyenne Haslett

Dec 17, 2021, 11:57 AM EST

UK reports highest daily cases ever

The United Kingdom reported 93,045 new cases in the last 24 hours, breaking a daily record for the third day in a row.

A large eletronic board at Waterloo station urging people to get boosted as the government accelerates it's Covid-19 booster program to get all adults vaccinated before the end of the year to stop the rapid rise in cases in London, Dec. 17, 2021.
Amer Ghazzal/Shutterstock

PHOTO: A steady stream of patients arrives at The Royal London Hospital in Whitechapel, London, Dec. 16, 2021.
A steady stream of patients arrives at The Royal London Hospital in Whitechapel, London, Dec. 16, 2021. The Omnicron variant has seen the largest number of infections in a single day on December 15th. The number has risen again on December 16th to the highest ever since the pandemic started.
Mark Thomas/Shutterstock

The total number of cases over the last week now stands at 477,229, a 38.6% increase from the previous week.

-ABC News' Guy Davies

Dec 17, 2021, 11:39 AM EST

Rockettes canceled due to breakthrough cases

Friday's four Radio City Rockettes shows have been canceled due to breakthrough COVID-19 cases in the New York City production.

Radio City Rockettes perform at the 89th Annual Rockefeller Center Christmas Tree Lighting Pre-Tape at Rockefeller Center on Nov. 30, 2021 in New York City.
James Devaney/GC Images

Plans for future shows haven't been determined. 

-ABC News' Aaron Katersky

Dec 17, 2021, 11:35 AM EST

CDC studies find schools can test kids rather than quarantine 

The Centers for Disease Control and Prevention on Friday endorsed a practice in schools called “test-to-stay,” which allows unvaccinated kids and staff to test instead of quarantine after being exposed to COVID-19.

The CDC says the practice can be employed in addition to other mitigation measures, such as vaccination and at least 3-feet of physical distance among students wearing masks.

The new guidance follows two studies out of Los Angeles County, California, and Lake County, Illinois. Both studies found no significant transmission in school when test-to-stay was used.

The studies were conducted before the omicron variant was detected in the U.S.

-ABC News' Anne Flaherty