Chemokine receptor expression on CD4+ and CD8+ T cell populations in acute DENV, ZIKV, and DENV/ZIKV patients. Peripheral blood mononuclear cells (2 × 105) were stained with mAb against surface markers CD3, CD8, CD4, CCR5, CX3CR1, and CXCR3. The expression of CCR5, CX3CR1, and CXCR3 on CD4+ (a) and CD8+ T cells (e) was showed in contour plots from one representative exposed donor, DENV‐, ZIKV, and DENV/ZIKV‐patients by flow cytometry. Frequency, median, 25th and 75th percentile of CCR5+ (b), CX3CR1+ (c), and CXCR3+ (d) CD4+ T cells from acute viral patients were compared between them and with those in exposed healthy controls. The same strategy was used for CD8+ T cells (f–h). Patient 2 in late acute phase (22 days of illness) was show as open squares. Statistical significance of differences between groups was determined by using two‐tailed Mann–Whitney test, where p < 0.05 were considered significant (*p < 0.05; **p < 0.01).