CCL2 and COVID-19: We observed significant changes in the mRNA expression level of inflammatory markers associated with COVID-19 severity including IL-1β, TNF-α, CCL2, and CXCL10 in our SARS-CoV-2 infected Vero E6 cells (Figure 2A); suggesting that Vero E6 cells may be used to study the inflammatory events associated with COVID-19 and modelling the severe stage of the disease in vitro.