The coronavirus disease-19 (COVID-19) signs mostly include fever and respiratory symptoms (unusual viral pneumonia by SARS-Coronaviruses 2 or SARS-CoV-2). The Receptor-Binding Domain (RBD) of COVID-19 and SARS-CoV are similar, causing cross-reactivity of anti-SARS-CoV antibodies with associated spike protein, exerting promising implications for rapid development of vaccines and therapeutic antibodies against COVID-19. ACE2 is the SARS TMPRSS2 for spike (S) protein receptor for initiation of infection; hence, it is a target for pharmacological intervention. Furthermore, designing novel monoclonal antibodies binding specifically to COVID-19 RBD is essential. A viral S proteins (TMPRSS2) was proposed for clinical use by blocking the viral intake by cell.