Once flu season begins, the U.S. will have to worry about not one, but two contagious viruses. “The real risk is that we’re going to have two circulating respiratory pathogens at the same time,” said Dr. Robert Redfield, Director of Centers for Disease Control and Prevention (CDC) during a TIME 100 Talks discussion with senior health writer Alice Park. “We know flu by itself can cause substantial morbidity and mortality and hospital utilization,” especially for elderly people and those who have underlying health conditions. With the new coronavirus wreaking devastation in these groups and others, “this could be really a very, very difficult situation.” Getting a flu vaccine is one way to help prevent influenza. But even though flu vaccines are safe and often quite effective, they aren’t very popular. “Historically, less than half of Americans get flu vaccines,” Redfield said. “This is the year that I’m asking the American public to seriously reconsider, because that decision may make available a hospital bed for somebody else that really needs it for COVID.”