President Biden will ban most non-U.S. citizens who have recently visited South Africa from entering the country over concerns of a new variant of COVID-19, an official told Reuters on Sunday. “We are adding South Africa to the restricted list because of the concerning variant present that has already spread beyond South Africa,” Dr. Anne Schuchat, the principal deputy director for the Centers for Disease Control and Prevention, told Reuters. The U.S. is also expected to ban non-citizens traveling in from countries that still have open borders, according to Reuters, a group of countries that include the United Kingdom, Brazil, and the European Union. While research is early, scientists fear that the South African-originating variant—named 501Y.V2—could be more resistant to antibodies.