CD4 and infection: IFN-γ produced by CD4+ Th1 cells is known to be a keycytokine in promoting schistosome vaccine-induced protection, while IL-10is a key inhibitor of the process [30].Furthermore, as the CD4+ T-cell mediated immune response playsa central role in the control of schistosoma after natural infection or vaccination [6], [30], we determined whether CD4+T cells are responsible for the production of these two cytokines.