Several cell-based assays are now being used to determine the correlates of protection in groups and individuals with symptomatic COVID-19 immunity and vaccine reactions. The cell-based assays have demonstrated high levels of concordance with living as well as pseudotyped virions of the novel coronavirus. For a return to normalcy and the resumption of economic activity across the globe, national borders will need to be reopened and businesses will have to start functioning as before. However, for this to happen, safe and effective vaccines, as well as other treatment modalities, will have to be developed and implemented as soon as possible. Hence, scientists need to be able to appraise the factors that determine protective immunity against the SARS-CoV-2 virus, also known as the severe acute respiratory syndrome 2. This is because the SARS-CoV-2 is known to be a major causative agent of COVID-19.






