Humoral response in orally immunized C57BL/6(H-2d) mice and protection assay after a challenge with T. gondii cysts. (A) Cyst number per brain. a = p < 0.05: SAG1+Boost vs. SAG1, Control and naïve. (B) Determination of specific anti-rSAG1 humoral response in C57BL/6 (H-2d) mice. Specific IgGt titers in sera from vaccinated mice were determined by ELISA. a = p < 0.001: SAG1+Boost vs. SAG1, Control and naïve. Control: mice vaccinated with pzp200-infiltrated leaf extracts, SAG1: pKnS-infiltrated leaf extracts, SAG1+Boost: mice vaccinated with pKnS-infiltrated leaf extracts plus rSAG1 prime boost. Statistical analysis was performed by one-way analysis of variance (ANOVA) using the Bonferroni's Multiple Comparison Test. Results are expressed as the means value ± S.E.M and represent one of two similar experiments. Values for each serum sample were determined in duplicate.