It is important to note, however, that the results show that Plasmodium antigen specific CD8+ IFN-γ responses were detected in rhesus only in the presence of detectable CD4+ T cell responses, consistent with the profile of CD4+ T cell dependent CD8+ Type 1 responses observed in malaria DNA vaccine studies in humans as measured by T cell depletion and enrichment ELIspot assays and RT-PCR [44,41,40]. Here, CD4 is linked to malaria.