On Friday, the World Health Organization categorized a new strain of COVID-19 that was recently detected in southern Africa as a "variant of concern."
The WHO's Advisory Group on SARS-CoV-2 Virus Evolution says the omicron variant is potentially more transmissible and could cause more severe disease than other COVID-19 variants.
While it's unclear where the new variant, originally named B.1.1.529, actually arose, it was first discovered in South Africa on Wednesday. It's since been seen in travelers to Hong Kong and Botswana.
Joe Phaahla, South Africa's health minister, said the variant was linked to an "exponential rise" of cases in the last few days, although experts are still trying to determine if the new variant is actually responsible.
Several countries, including the European Union, have already moved to suspend travel to southern Africa in the hopes of limiting the spread of the variant.
CNN reports that that genomic scientists say the new variant has an "unusually high" number of mutations that cause the virus to have more of the key spike proteins it uses to get into the healthy cells it attacks.
NPR says the new variant also has twice as many mutations as the delta variant, which caused a new surge in cases this summer.