CD8A and parasitic infectious disease: Transferring CD8+ T cells into infected mice 24 h after sporozoite injection could still reduce the time to 0.5% parasitemia (Fig. 3), consistent with a previous in vivo study (52) and with our in vitro killing assay where a reduction in the number of sporozoite-infected hepatocytes can be observed within 24 h after the addition of CD8+ T cells (64).