Plasma levels of IFN-γ, TNF-α and IL-10. Levels of circulating IFN-γ and TNF-α were determined by ELISA, IL-10 was determined by cytometric bead array (CBA) in malaria-naïve donors (n = 12) and P. vivax-infected donors (n = 17). A. IFN-γ. B. TNF-α. C. IL-10. Mann–Whitney test was used for comparison and the result was expressed as the median with interquartile range. P values are indicated in the graphs.