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:
Cornell moves exams online due to 'substantial' number of suspected omicron cases
Cornell University is moving into a "level red" alert after a "significant" number of suspected omicron cases were detected among student samples.
"While we must await confirmatory sequencing information to be sure that the source is Omicron, we are proceeding as if it is," university president Martha Pollack wrote in a letter to the community.
All final exams will be online beginning Tuesday, Pollack announced, and libraries and fitness centers are closed.
All undergraduate events are canceled, as is Saturday's recognition ceremony for December graduates, Pollack said.
Cornell has recorded more than 600 confirmed cases among students and staff in the last week alone, according to the university dashboard. While no infected students are seriously sick, Pollack said the university has "a role to play in reducing the spread."
-ABC News' Arielle Mitropoulos, Chris Donato
Omicron 'spreading at a rate we have not seen,' WHO says
"Omicron is spreading at a rate we have not seen with any previous variant," World Health Organization Director-General Dr. Tedros Adhanom Ghebreyesus warned Tuesday.
Omicron has been reported in 77 countries, he said, adding that the new variant is likely in most countries.
Tedros said health officials are "concerned that people are dismissing omicron as mild."
"Even if omicron does cause less severe disease, the sheer number of cases could once again overwhelm unprepared health systems," he said.
-ABC News' Christine Theodorou
England to lift travel ban on southern African nations
British Transport Secretary Grant Schapps announced Tuesday that England will remove all southern African nations from its travel red list.
After the omicron variant was first discovered in South Africa and Botswana in November, several countries around the world, including England and the United States, imposed travel bans on a swath of nations in southern Africa.
The World Health Organization warned that blanket travel bans will not prevent the international spread of omicron, deemed a "variant of concern," and that restrictions place a heavy burden on lives and livelihoods.
The countries of Angola, Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, Nigeria, South Africa, Zambia and Zimbabwe will be taken off England's travel red list on Wednesday at 4 a.m. GMT, according to Schapps, who noted that all current testing measures remain in place.
"As always, we keep all our travel measures under review and we may impose new restrictions should there be a need to do so to protect public health," Schapps wrote on Twitter Tuesday.
Despite the travel bans, the heavily mutated variant has taken a foothold in London. British Health Secretary Sajid Javid told Parliament on Monday that omicron accounts for more than 44% of COVID-19 infections in the U.K. capital and it's expected to become the dominant variant there by Wednesday, overtaking the highly contagious delta variant.
Addressing Parliament again on Tuesday, the health secretary called omicron "a grave threat" and said the "race" to get as many people vaccinated and boosted "is new national mission."
"Scientists have never seen a COVID-19 variant that’s capable of spreading so rapidly," Javid said.
-ABC News' Christine Theodorou
Proportion of omicron cases growing in US, CDC data show
The proportion of new cases of the omicron variant in the United States is steadily growing, according to new data released Tuesday by the Centers for Disease Control and Prevention.
The data show that omicron now accounts for 3% of all new COVID-19 cases nationwide, just over two weeks after it was first detected in the U.S. Last week, omicron was estimated to account for just 0.4% of all new cases nationwide. Epidemiologists, including Dr. John Brownstein, an ABC News contributor, cautioned that these figures are rough estimates.
Currently, the delta variant still accounts for the vast majority -- nearly 97% -- of new cases in the U.S., according to the CDC. More than half the country -- at least 34 states and Washington, D.C. -- have reported cases of the newly discovered variant.
-ABC News' Arielle Mitropoulos
New York state sets another daily case record
Nearly 22,000 positive COVID-19 test results were reported in New York state in the last 24 hours, according to Gov. Kathy Hochul's office -- breaking a single-day record set the day before.
The 21,908 positive COVID-19 test results are out of 290,930 results reported -- for a 7.53% positivity rate.
Demand for testing also continues to rise, with about 27,000 more people getting tested on Friday.
"This is not like the beginning of the pandemic. We are prepared for the winter surge because we have the tools at our disposal," Hochul said in a statement. "Getting vaccinated, getting the booster and wearing a mask are critical to avoiding getting seriously ill from COVID-19, so don't take a chance."
-ABC News' Joshua Hoyos