In the last couple of decades, there have been three major epidemics where animal viruses have infected humans. The most recent outbreak is caused by the SARS-CoV-2 virus, a.k.a. 2019-nCoV, which can result in corona virus disease 19 (COVID-19). Before this virus, there were outbreaks of SARS-CoV and MERS-CoV, which cause Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), respectively.