Coronavirus creates a flu season guessing game

Measures to control the spread of COVID-19 have all but stopped flu from spreading in the Southern Hemisphere during its expected flu season. But the Northern Hemisphere may not get so lucky. As public health officials brace for increased demand on hospitals and COVID-19 testing infrastructure, researchers have few clues about how SARS-CoV-2 will interact with other viruses. They're eager to collect more information on how one virus might change a person's susceptibility to another, and how coinfection with multiple viruses at once might change outcomes. Meanwhile, many countries are stepping up flu vaccination efforts to blunt the double whammy.