Protective anti-idiotype vaccine against Schistosoma mansoni infection

Vaccine development may be the most cost-effective way to ultimately control schistosomiasis, a disease that affects 200 million people worldwide. Vaccine development in schistosomiasis has centered on identifying key surface antigen(s) on schistosomula, the migrating larval form of the parasite, and cloning these antigens through molecular biology-derived technology. This strategy will be most effective if the key surface epitopes are protein in nature. An alternative strategy is to develop anti-idiotypic antibody vaccines that take advantage of the unique antigen-mimic quality of certain anti-ids. In the present investigation, a polyclonal anti-id was prepared and used to protect mice in vivo. Our data indicate that an anti-id vaccine directed against defined schistosome antigens can be effective in inducing active resistance against a challenge with S. mansoni cercariae. Enhanced resistance can be induced without the use of adjuvants and following even a single immunization. Such studies show that anti-id-based vaccines can provide a viable alternative to recombinant subunit vaccines, particularly if carbohydrate epitopes are involved in the induction of resistance.