A departures screen displays a cancelled flight to Johannesburg and a message to contact the airline for a scheduled flight to Capetown, at London's Heathrow Airport, Friday, Nov. 26, 2021. The U.K. announced that it was banning flights from South Africa and five other southern African countries effective at noon on Friday, and that anyone who had recently arrived from those countries would be asked to take a coronavirus test. (AP Photo/Alberto Pezzali)