ABSTRACT
This study assessed the effectiveness of autoclaved cercarial vaccine [ACV] in protection against Schistosoma mansoni infection in 125 Swiss albino mice classified into two main groups: GI: a control group. Gil: a test vaccinated with ACV, in a single dose of 0.1ml of 10[4] ml ACV [G.IIa], double dose; 0.2ml [G.IIb] and two single doses 2 weeks apart [G.IIc]. Four weeks later, all mice were challenged with S. mansoni cercariae and sacrificed 10 weeks post infection [P.I.]. The results revealed that the vaccine in a single dose [G.IIa] induced a high level of protection against S. mansoni infection. There was a significant reduction in the mean number of adult worm [91.12%], ova/gram liver [91.87%], ova/gram intestine [89.09%] and number and size of granulomas in liver [92.92% and 43.53% respectively]. Besides, ACV induced a significant increase in the level of IL-10 mRNA expression as compared to the control group