1. Introduction
The emergence of coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a large-scale global outbreak and is a major public health crisis [1]. The serious epidemic situation has highlighted the need for effective therapeutic and preventive solu-tions to reduce the perils and transmission of the disease. A num-ber of countries have accelerated the process of clinical trials to develop an effective and safe vaccine to curtail the current ongoing pandemic [2].