[Intranasal or intragastric vaccination of mice with recombinant Schistosoma japonicum ferritin induces immune protection against challenge infection].

Objective: To test the immune protection against challenge infection in mice vaccinated intranasally or intragastrically with recombinant Schistosoma japonicum (S.j) Ferritin (rSjFer).

Methods: Mice were divided into 8 groups each with 10 mice. They were immunized intragastically with rSjFer, CTB, rSjFer + CTB and intranasally with rSjFer, CTB and rSjFer + CTB respectively. PBS was used intragastically or intranasally as control groups. The mice were challenged with 40 +/- 1 S. j cercariae per mouse 2 wk after the third vaccinization. Forty-five days later, mice were killed and perfused, and the adult worms and eggs were counted. Serum and fecal samples were obtained before the first immunization and the challenge infection. IgA and IgG in sera and sIgA in feces were detected by ELISA.

Results: The worm reduction rate was 3.98%, 3.77%, 25.57% in the intragastric vaccination groups and 7.59%, 4.50%, 33.35% in the intranasal vaccination groups respectively. The egg reduction rate was 3.76%, 2.46%, 34.75% and 4.40%, 0.06%, 60.10% respectively.

Conclusion: This study showed that a significant immune protection against Schistosoma japonicum infection was induced by mucosal (intranasal and intragastic) vaccination with rSjFer.