Samples from patients with acute Dengue (n 12), Influenza A (n 12), Adenovirus (n 3) infections were collected at the onset of disease (represented in these patients by fever >38° C), after 5–7 days and after recovery (∼21 days) and frequency of CD8 T cell population expressing activation (CD38/HLA-DR) and proliferation (Ki-67) markers was measured (Figure 4 A). Here, CD38 is linked to dengue disease.