A fast-spreading new strain of the Coronavirus, which was first detected in South Africa, has gone global, causing a new wave of COVID concern and travel restrictions. 

The new strain called “Omicron” is the 7th strain that has been significant enough to earn the rank of a Greek letter, which only serves to show how dangerous the variant could be compared to the other variants. Experts report that this strain is thought to be more serious because it has three major mutations.

The race to close borders has been swift. Omicron was first reported by South African public health officials to the World Health Organization (WHO) on Wednesday, November 24. By Sunday evening, 56 countries had closed their borders, and many more have implemented tighter restrictions for testing and quarantine for unvaccinated travelers. 

Experts cautioned that border-closing is not a proven strategy to reduce the spread and can cause economic hardship, especially in less wealthy countries, and are not necessarily effective. “I well understand the concern of all countries to protect their citizens against a variant that we don’t yet fully understand,” WHO head Tedros Adhanom Ghebreyesus said. “But I am equally concerned that several member states are introducing blunt, blanket measures that are not evidence-based or effective on their own, and which will only worsen inequities.”

President Biden acknowledged that closing the border and tightening restrictions would not keep out the new variant: “Sooner or later we are going to see new cases of this new variant here in the United States and we’re going to have to face this new threat just as we have faced the ones that came before it.” Experts emphasize that proven strategies for reducing the spread include receiving a vaccine, masking, and social distancing, and Biden reassured that Americans will overcome the disease’s new challenges.