SARS-CoV-2: A Piece of Bad News

A shocking third face appeared from coronaviruses (CoV) in late 2019 follows SARS (Severe acute respiratory syndrome-CoV) in 2003 and MERS (Middle East respiratory syndrome –CoV) in 2012; it’s a novel coronavirus now called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; formerly called 2019-nCoV). First emerging in China, it has spread rapidly across the globe, giving rise to significant social and economic costs and imposing severe strain on healthcare systems. Despite many attempts to control viral spread has been futile, the only old practice of containment including city lockdown and social distancing are working to some extent. Unfortunately, specific antiviral drugs and vaccines remain unavailable. Many factors are encountered to play an essential role in viral pathogenesis. These include a broad viral-host range with high receptor binding affinity to various human tissues, viral adaptation to humans, a high percentage of asymptomatic infected carriers, prolonged incubation, and viral shedding periods. A wide variety of pulmonary and extrapulmonary tissue damage mechanisms including direct cell injury or immune-mediated damages involving the immune cells, up-regulation of pro-inflammatory cytokines, and antibody dependent enhancement that can result in multi-organ failure. In this article, we summarise the evidence on the various steps in SARS-CoV-2 pathogenesis and immune evasion strategies to assess their contribution to our understanding of unresolved problems related to SARS-CoV-2 prevention, control, and treatment protocols.