First five omicron cases detected in South Korea

Five cases of the COVID-19 omicron variant were confirmed in South Korea on Wednesday, making it the latest to join more than 20 countries that have detected the new coronavirus strain.

South Korean officials said the cases were linked to five people who traveled to Nigeria and returned at the end of November, The Associated Press reported. The country is requiring all travelers arriving in South Korea to quarantine for 10 days and has banned travelers coming from eight nations in South Africa.

Omicron, which was first detected in South Africa at the end of last month, has now been found around the world, from Sweden to Australia. The U.S. and other countries recently enacted international travel bans to stop the spread of the worrying variant, though the World Health Organization has not yet ruled whether omicron is more transmissible or deadly than previous variants, including the dominant delta variant.

But the news comes as South Korea is grappling with a surge in coronavirus cases, with more than 5,000 reported yesterday, a record. Last month, South Korea eased its social distancing and coronavirus restrictions, a move some health care officials in the country have criticized.

South Korea has reported 452,320 total cases since the pandemic began, with 3,650 total deaths. About 79 percent of the population is fully vaccinated.

Vaccines, with booster shots, are thought to hold adequate protection against omicron, but it's unclear how effective they will be. Vaccine makers Moderna and Pfizer are racing to tweak their vaccines to better protect against omicron, The New York Times reported.