Covid-19: Pathophysiology; Mechanism of Transmission and Possible Molecular Drug Target for Management

Coronavirus disease 2019 (COVID-19) is caused by Severe Acute Respiratory Syndrome Coronaviruses 2 (SARS-CoV-2). At present, it is a potentially fatal disease and is of great global public health concern. The pathophysiological understanding of the mode of transmission of COVID-9 and the possible molecular targets are exploring successively to fight against this contagious disease. In this pandemic situation, a large number of countries have been forced to do social distancing and lockdown. The two main pathways of SARS-CoV-2 transmission include (1) droplet infection via the respiratory secretions or by close person to person contact, whereas (2) faecal to oral route transmission is also possible. Thus, the route of entry of SARS-CoV-2 is through the nasal and or oral cavity. Here, we briefly reviewed the current knowledge about COVID-19, considering the potential explanation of the mode of transmission and the different possible molecular drug targets. We highlighted potential approaches to address the antiviral therapy inhibiting the replication of SARS-CoV-2 in the host targeting (a.) RNA-dependent RNA polymerase (b.) serine protease and (c.) proteolytic activation pathways or the cell membrane receptor called the angiotensin- converting enzyme-2 (ACE2). The recently exercised immuno-enhancement therapy to fight against SARS-CoV-2 and treatment strategy using drug combination are also explored here in this review.