COVID-19 stands for CoronaVirus Disease-19 and is caused by betacoronavirus. Alpha corona descended from bat gene virus and has been linked to feline corona and canine corna. There are 7 known coronaviruses that have been linked to human disease so far. Beta coronavirus also comes from bat gene visus and has been lined to human SARS and MERS. Both alpha and beta can infect humans. The SARS-Cov-2 virus has 96% similarity to RaTG13 virus in bats.