Pandemic lessons from the past The World Health Organization says it’s still too early to call the COVID-19 coronavirus a pandemic â but the potential for it to become so is not far away. A pandemic means the worldwide spread of a new disease. For example, an influenza (flu) pandemic occurs when a new influenza virus emerges and spreads around the world, and most people do not have immunity. Worried about COVID-19? Check out some of the pandemic resources we created as part of our 2018 project Unmasking Influenza, which commemorated the centenary of the 1918-19 Spanish Flu pandemic. Illustration: U.S. Food and Drug Administration |