Abstract
Coronaviruses (CoV) belong to enveloped single-stranded RNA viruses. Six COV namely HKU1, NL63, 229E, OC43, SARS, and MERS have been detected in humans, until December 2019 an outbreak of the novel coronavirus, known as "COVID-19/SARS-CoV-2", in appeared Wuhan, China. As a consequence, life has changed dramatically and many people and health authorities are left confused about what they are to do to avoid dissemination of catastrophe. Even though much is identified about the mortality of the clinical phase of COVID 19 disease (symptoms ranging from the mild common cold to severe respiratory disease), but much less is understood about its pathophysiology. It has triggered infections and deaths more than SARS or MERS due to its high speed of transmission. Hence, SARS-CoV-2 is a considerable health and economic issue that can be horrific especially for immunocompromised or elderly people. In the last 18 years, we have been witness for the emergence of three extremely pathogenic zoonotic coronaviruses throughout history.