CD4 and Lassa fever: Our previous studies have shown that PBMCs isolated from amicrofilaremic LF patients secrete more IL-17 levels upon activation with αCD3/αCD28 compared to endemic normals (Arndts et al. 2012) and moreover that Th17 cell frequencies are elevated in hyperreactive onchocerciasis and reduced in endemic normals accompanied with elevated CD4+IFN-γ+ frequencies (Katawa et al. 2015).