As the COVID-19 pandemic has swept the globe, more than 5.3 million people have died from the disease worldwide, including over 797,000 Americans, according to real-time data compiled by Johns Hopkins University's Center for Systems Science and Engineering.
Just 60.7% of the population in the United States is fully vaccinated against COVID-19, according to data from the Centers for Disease Control and Prevention.
Four cases of the omicron variant have been detected in Washington, D.C., health health officials announced Sunday.
The first case is a woman who recently traveled to Florida and New York.
The second case is a woman who traveled to Maryland during Thanksgiving, health officials said.
The third case is a man with no known travel, according to health officials.
The fourth case is a woman who traveled to Virginia during the Thanksgiving, health officials said.
All four patients are fully vaccinated; however, it is unclear if they have received booster shots, health officials said.
-ABC News' Beatrice Peterson
The United Kingdom raised the COVID-19 alert level on Sunday, citing a rapid increase in cases of the omicron variant.
The U.K. has detected 3,137 omicron cases so far, according to the GISAID tracker.
In an address to the nation Sunday, British Prime Minister Boris Johnson said the data on the severity of the new variant would become more apparent in the coming weeks. Still, at this stage, Johnson said early evidence shows that omicron is spreading much faster than the highly contagious delta variant.
Vaccine protection against symptomatic disease from omicron is reduced and hospitalizations from the new variant are already occurring. Cases and hospitalizations are likely to increase rapidly, Johnson warned.
In an effort to battle the "tidal wave of omicron" and avoid imposing further restrictions, the prime minister announced his government will begin rolling out 1 million booster doses of the COVID-19 vaccine per day across all four nations of the U.K. -- England, Scotland, Wales and Northern Ireland. He vowed that everyone over the age of 18 will have the opportunity to receive a booster shot before the New Year. The British Army will be deployed to facilitate and accelerate the emergency rollout, according to Johnson.
-ABC News' Christine Theodorou and Mike Trew
Nearly a month after imposing additional rules to fight rising COVID-19 infections, Austrian authorities will now allow vaccinated people to participate in public life starting Sunday.
Lockdown restrictions will still apply to unvaccinated individuals.
According to Austria's health ministry, 68% of the country's population is fully vaccinated
But Austria's tough response to rising COVID infections doesn't end there. The health minister, Wolfgang Mueckstein, announced that starting Feb. 1 and going through Jan. 2024, COVID vaccines will be mandatory, for all residents aged 14 and over
At the end of each quarter, residents who remain unvaccinated face fines up to $4,074.
The mandate, which still needs to be approved by parliament, will include exemptions for women who are pregnant, children under the age of 14 and people who cannot be vaccinated for health reasons.
-ABC News' Christine Theodorou
More than 50 million Americans have now received a COVID-19 booster shot, according to newly updated federal data.
More than half of fully vaccinated people 65 years and older have received a booster.
On average, about 2.03 million total shots are being administered each day, the data shows. More than half -- 1.1 million -- are booster doses.
-ABC News' Arielle Mitropoulos
The World Health Organization said Thursday that preliminary data indicates hospitalizations in South Africa remain low, offering "signs of hope," despite the fact that the omicron variant is spreading rapidly and weekly COVID-19 cases on the African continent have surged by 93%.
In the week ending on Dec. 5, southern Africa recorded a 140% hike in COVID-19 cases, the highest of any region on the continent for that period, mainly driven by an uptick in South Africa, according to the WHO. While researchers are still working to determine whether omicron is fueling the surge, the WHO said that emerging data from South Africa indicates the new variant may cause less severe illness. Data on COVID-19 hospitalizations across South Africa between Nov. 14 and Dec. 4 show that intensive care unit occupancy was only 6.3%, which the WHO said is very low compared with the same period when the country was facing the peak linked to the delta variant in July.
Furthermore, data from the same two-week period from one of the South African health districts most impacted by omicron show that out of more than 1,200 hospital admissions related to COVID-19, there were 98 patients receiving supplemental oxygen and only four on ventilators. The WHO cautioned that the data is "very preliminary with a small sample size and most of the people admitted to the health facilities were under the age of 40."
Since omicron was first identified in southern Africa in November, confirmed cases of the variant have been reported in 57 countries around the world. In an effort to prevent the spread of the new variant, more than 70 countries have imposed travel bans that are mainly targeting southern African nations, some of which have yet to report any omicron cases, according to the WHO.
"With Omicron now present in nearly 60 countries globally, travel bans that mainly target African countries are hard to justify," Dr. Matshidiso Moeti, the WHO's regional director for Africa, said in a statement Thursday. "Through the diligent surveillance efforts of African scientists, the new variant of concern was first detected on this continent, but it's unclear if transmission was taking place silently in other regions. We call for science-based public health measures to counter the spread of COVID-19. The travel restrictions come at the height of the end-of-year tourist season, ravaging Africa's economies, with a knock-on impact that is potentially devastating to the health of Africans."
