CD4 and COVID-19: • Increased activation profile of CD4+, CD8+ and plasmablasts was seen in COVID-19 patients.• Interestingly severe cases were associated with activated profile of CD4+ T cells, lower number of TFH cells and exhaustive CD8+ T cells.• Increased levels of serum AST, CRP, and creatinine kinase was observed.• CRP was suggested as the predictive disease marker.