COVID -19: From the Molecular Mechanisms to Treatment.

The 2019 novel coronavirus (SARS-CoV-2) causes severe pneumonia called COVID-19 and leads to severe acute respiratory syndrome with a high mortality rate. The SARS-CoV-2 virus in the human body leads to jumpstarting immune reactions and multi-organ inflammation, which has poorer outcomes in the presence of predisposing conditions, including hypertension, dyslipidemia, dysglycemia, abnormal adiposity, and even endothelial dysfunction via biomolecular mechanisms. In addition, leucopenia, hypoxemia, and high levels of both cytokines and chemokines in the acute phase of this disease, as well as some abnormalities in chest CT images, were reported in most patients. The spike protein in SARS-CoV-2, the primary cell surface protein, helps the virus anchor and enter the human host cells. Additionally, new mutations have mainly happened for spike protein, which has promoted the infection's transmissibility and severity, which may influence manufactured vaccines' efficacy. The exact mechanisms of the pathogenesis, besides molecular aspects of COVID-19 related to the disease stages, are not well known. The altered molecular functions in the case of immune responses, including T CD4+, CD8+, and NK cells, besides the overactivity in other components and outstanding factors in cytokines like interleukin-2, were involved in severe cases of SARS-CoV-2. Accordingly, it is highly needed to identify the SARSCoV-2 biomolecular characteristics to help identify the pathogenesis of COVID-19. This study aimed to investigate the biomolecular aspects of SARSCoV-2 infection, focusing on novel SARS-CoV-2 variants and their effects on vaccine efficacy.