Coronavirus disease 2019 (COVID-19) is a respiratory system disease that results in flu-like symptoms. It is caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) which was initially transmitted from either sea animals, wild animals like bats, or pet animals like dogs, and cats to humans. Since the occurrence of the first human COVID-19 case in China in 2019, the disease uses a trans-human transmission pathway. Its pathogenesis is almost similar to other respiratory diseases.