At least 10 people on board have tested positive for the virus.
As the COVID-19 pandemic has swept the globe, more than 5.2 million people have died from the disease worldwide, including over 785,000 Americans, according to real-time data compiled by Johns Hopkins University's Center for Systems Science and Engineering.
Just 59.6% of the population in the United States is fully vaccinated against COVID-19, according to data from the Centers for Disease Control and Prevention.
COVID-19-related hospital admissions in the U.S. are up by 20% since the beginning of November, according to federal data. About one-quarter of the patients are between the ages of 18 and 49.
Nearly 58,000 Americans are in the hospital with COVID-19, including more than 1,300 children, according to federal data.
-ABC News' Arielle Mitropoulos
In South Africa, the National Institute for Communicable Diseases reported 8,561 new COVID-19 cases on Wednesday -- which is nearly double the 4,373 new cases reported on Tuesday.
Seventy-two percent of the new cases were diagnosed in Gauteng province. South African President Cyril Ramaphosa said Sunday that the omicron variant was responsible for most of the infections found in Gauteng over the last two weeks and that the variant is now showing up in all other provinces.
-ABC News' Christine Theodorou
Forecast models used by the CDC -- the COVID-19 Forecast Hub at UMass Amherst -- predict weekly death totals and hospital admissions to increase over the next four weeks.
The model predicts that more than 15,000 Americans will die over the next two weeks, with a total of nearly 810,000 deaths recorded by Christmas.
-ABC News' Arielle Mitropoulos
South Korea on Wednesday confirmed its first cases of the omicron variant.
The Korea Disease Control and Prevention Agency said the new variant was initially detected among three people -- a couple who arrived from Nigeria on Nov. 24 and their friend who drove them home from the airport. Since then, the variant was found in two other people who also traveled to Nigeria and returned to South Korea on Nov. 23, bringing the total of confirmed cases to five.
Health authorities are conducting genetic sequencing tests on the couple's child and relatives of the friend who drove them home to determine if they were also infected, according to the Korea Disease Control and Prevention Agency.
In an effort to fend off the omicron variant, which was first identified in southern Africa last week, South Korea has banned foreign short-term travelers from eight southern African nations. South Korean citizens arriving from those countries must quarantine for at least 10 days, regardless of their vaccination status.
South Korea's daily tally of newly diagnosed COVID-19 infections exceeded 5,000 on Wednesday for the first time since the start of the pandemic. The surge, which officials attributed to the highly contagious delta variant, has pushed COVID-19 hospitalizations and deaths in the country to record highs.
The Korea Disease Control and Prevention Agency said most of the 5,123 new cases were reported in the capital, Seoul, and its surrounding metropolitan region, where officials said earlier that more than 80% of intensive care units designated for COVID-19 patients were already filled.
-ABC News' Joohee Cho
