FIG. 5.
Parasitemia and survival percentages for immunized mice after challenge with T. cruzi. Mice were immunized with saline solution (□) or pCMV4 (▵), pCMV4.11 (○), and pCMV4.11.70 (⧫). Six mice per group were challenged with 103 T. cruzi blood trypomastigotes (Y Brazil strain) 9 weeks after the fourth immunization (A). The levels of parasites in the bloodstream were determined individually for three mice per group using a Neubauer chamber. Values are means ± standard deviations (SD) of the means of results for three mice. (B) Survival percentages of immunized mice challenged 2 weeks after the last immunization were regularly recorded.