Responses of the heathy blood donor controls of endemic area were negative or lower than those promoted by MultiAAA and MultiGPGPG, with the exception of total frequencies of CD4 and CD8 T cells producing TNF-α (Figures 9e, f) and, total frequencies of CD8 T cells producing IFN-γ (Figure 9g), in response to SLA antigen, suggesting that even these blood donors, who tested negative for the presence of the cross-reactive Chagas Disease antigen can react with the mixture of total Leishmania proteins that compose the SLA antigen. Here, CD4 is linked to Chagas disease.