Evaluation of the protective ability against T. gondii infection. (A) Six immunized mice per group were infected intraperitoneally with 1 × 10³ tachyzoites of T. gondii RH strain 4 weeks after the last immunization. Survival was monitored daily for 28 days after challenge. (B) Another six immunized mice per group were infected intragastrically with 20 cysts of T. gondii PRU strain and the cyst burden in the brain of vaccinated mice was counted 4 weeks later. The mean number of cysts in every mouse group was based on each mouse brain cyst in the group. Asterisks mark the significant difference: *p < 0.05; **p < 0.05. Each bar represents the mean OD (± SD).