ELISPOT assay for TEWETGQI-specific IFN-γ secreting cells before and after a T. cruzi challenge. Groups of A/J mice were immunized with Mock (Earle's 199 Medium), YF17DD virus, recombinant viruses (YF17D/E200/Tc and YF17D/NS2B3/Tc) or with TEWETGQI emulsified in Freund's Adjuvant. Spleen cells were obtained one week after the last dose (before challenge) or two weeks after challenge. A) Spleen cells response to YF17DD stimulus before challenge. B) Spleen cells response to TEWETGQI stimulus before challenge. C) Spleen cells response to TEWETGQI stimulus after challenge. Results represent IFN-γ producing cells (SFC) per 106 spleen cells. Statistically significant differences (ANOVA Tukey's test) are shown in the graphics.