Induction of IFN-γ secreting splenocytes in vaccinated mice before and after <i>T. cruzi</i> challenge.

<p>Groups of A/J mice were immunized once or twice with medium (mock) (○), YF 17DD vaccine (□), YF17D/NS2B3/Tc virus (•) and YF17D/ENS1/Tc virus (▾) or alternatively with Formulation 1 (50,000 PFU of YF17D/NS2B3/Tc and 50,000 PFU of YF17D/ENS1/Tc) (♦) and challenged or not with 250 <i>T. cruzi</i> trypomastigotes. Spleen cells of each mouse were obtained one week after the first dose (A and C), one week after the second dose (B and D) or two weeks after challenge (E) and after that, were stimulated <i>in vitro</i> with YF 17DD inactivated virus (A and B) or TEWETGQI-peptide (C, D and E) to assess cellular responses to YF peptides or to the <i>T. cruzi</i> peptide, respectively. Results represent IFN-γ producing cells (SFC) per 10⁶ spleen cells. Asterisks indicate statistically significant differences between groups of immunization in comparison to Mock (A and B) or in comparison to Mock and YF 17DD group (C, D and E) and were done by ANOVA Tukeýs test (***<i>P</i><0.0001; **<i>P</i><0.01; * <i>P</i><0.05).