The 2019/20 coronavirus pandemic is an ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus. Although for most people COVID-19 causes only mild illness, it can make some people very ill. More rarely, the disease can be fatal. Older people, and those with pre-existing medical conditions (such as high blood pressure, heart problems or diabetes) appear to be more vulnerable. The pandemic has caused global social and economic disruption, including the largest global recession since the Great Depression and global famine affecting 265 million people. It has led to the postponement or cancellation of sporting, religious, political, and cultural events, widespread supply shortages exacerbated by panic buying, and decreased emissions of pollutants and greenhouse gases. Schools, universities, and colleges have been closed either on a nationwide or local basis in 172 countries, affecting approximately 98.5 percent of the worl...