Sporozoite specific cytokine responses following RAS immunization under CQ cover. Percentages of IFNγ (A) and IFNγ and IL-2 (B) producing memory T cells were measured in RAS (n = 5) RAS-CQ (n = 4), naïve control (n = 5) and CQ-control (n = 4) mice, a day before challenge by intracellular staining after in vitro re-exposure of liver and spleen cells to P. berghei sporozoites (PbSPZ). Responses of CD4+ T cells (open area), CD8+ T cells (grey area) and CD4−CD8− T cells (dotted area) relative to total memory T cell responses are presented. Background responses to salivary glands were subtracted from PbSPZ responses for each individual mouse. Error bars represent standard error of the mean. NS = not significant.