Abstract
The novel coronavirus, designated as "Severe Acute Respiratory Syndrome Coronavirus 2" (SARS-CoV-2), is a new coronavirus that has evolved as a global pandemic recently, and it has created a widespread interest in coronaviruses causing human infections. This article compares the pathogenesis, distribution, clinical characteristics, and treatment of the three highly pathogenic coronaviruses that caused epidemics, namely, "Severe Acute Respiratory Syndrome Coronavirus" (SARS), "Middle East Respiratory Syndrome" (MERS), and SARS-CoV-2. This narrative review is prepared using the data compiled from literature search using relevant MeSH terms. The clinical manifestation of SARS-CoV-2 infection (COVID-19) is mild with relatively low fatality rate than the other two coronaviruses; however, its overall capability to cause explosive spread of the disease and reach a pandemic level is greater. Unlike SARS and MERS, COVID-19 has no accepted treatment protocols at present. Extensive studies and analyses on COVID-19 are necessary before making strong recommendations for or against any particular treatment, although some recent medications have shown great potential. COVID-19 still needs further investigation, where all of the lessons gained from previous outbreaks of SARS and MERS and the experience from the countries that managed COVID-19 seem to be the best approaches to counteract this new global hazard at present until effective preventive vaccines are available in sufficient quantity for mass vaccination programs worldwide.