American health officials say that anyone flying to the United States will soon need to show proof of a negative test for COVID-19. The new restrictions take effect on January 26. The order from the Centers for Disease Control and Prevention (CDC) requires air passengers to get a COVID-19 test within three days of their flight to the U.S. Airlines are ordered to stop passengers from boarding if they do not have proof of a negative test. Travelers can also provide documentation that they had the infection in the past and recovered. All air travelers aged two and older must follow the CDC order. However, passengers who only have a stopover in the U.S. before flying to another country do not have to provide proof of a negative COVID test.