CD27 and dengue disease: The percentage of naïve cells (CD27−) was decreased within the CD19+ B cell compartment between DENV patients and DENV-negative febrile controls (median, 78.1 vs. 69.0%; P < 0.05) and in DHF/DSS patients compared to mild dengue (median, 59.3 vs. 72.0%; P < 0.05) (Figure 1B).