Coronaviruses are a group of viruses that cause diseases in mammals and birds. In humans, coronaviruses mainly cause respiratory tract infections. It could be mild illness (like the common cold) or lethal illness, depending on the virus. The previously discovered coronaviruses are rhinoviruses, SARS, MERS, and the recent one is COVID-19. COVID-19 is an infectious disease that first originated from Wuhan, China in December 2019. Within a few weeks, it spread globally at an exponential rate and WHO declared it as a global pandemic on March 2020.