COVID-19 updates: Elizabeth Warren tests positive
The senator says she's experiencing "mild symptoms."
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:
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."
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
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.
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
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.
Plans for future shows haven't been determined.
-ABC News' Aaron Katersky
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
Harvard joins list of universities mandating boosters
Harvard University will require boosters for all eligible members of the community, school officials said Thursday.
Earlier this week, Harvard warned of an increase in cases, saying the rise can be attributed to social events following the Thanksgiving break.
Omicron is likely already on campus, university officials added.
Harvard joins a growing list of colleges and universities moving to require third doses next semester for those eligible. Other schools include Stanford, NYU, University of Notre Dame, Syracuse, Smith College and Wellesley College.
-ABC News' Arielle Mitropoulos