Humoral Immune Responses in Olive Baboons (Papio Anubis) Vaccinated With Either Radio-attenuated Schistosoma Mansoni Cercariae or Anti-idiotypic Antibodies

Abstract

Rabbits innoculated with purified baboon anti-cercariae antibodies (Ab 1) produced second generation antibodies 2 weeks post-vaccination as detected by radial immunodiffusion test. Anti-idiotypic antibodies (Ab2) purified from the second generation antibodies produced a 32% inhibition against Ab 1 binding to transformed schistosornula antigen compared to 87% inhibition produced by the schistosomula antigen when used in place of Ab2. Vaccination of5 baboons (Papio anubis) with the anti-idiorypic antibodies to irradiated Schistosoma mansoni cercariae resulted in intermediate antibody levels as compared to the high antibody levels obtained in sera of baboons exposed to irradiated cercariae. There was a 19% reduction in worm burden on perfusion of the 5 baboons compared to a 39% reduction in 5 baboons vaccinated with the irradiated vaccine. Vaccination with the anti-idiotypic antibodies resulted in significant reduction of pathology size following challenge with live unattenuated cercariae. Results presented in this work are considered highly significant because the anti-idiotypic vaccine markedly influenced schistosomiasis morbidity which is the main consideration in this disease.