Studies on amphistomiasis in Andhra Pradesh (India) VI. Immunization of lambs and kids with gamma irradiated metacercariae of Cercariae indicae XXVI.

The life span and the pathogenicity of amphistomes developing from Cercariae indicae XXVI (Paramphistomum epicilitum) were considerably reduced when the metacercariae were gamma-irradiated at 2 krad or 3 krad. The higher irradiation dose resulted in the complete absence of the flukes in infected animals. Single vaccination of lambs and kids with 3000 metacercariae irradiated at 2 krad or 3 krad stimulated a significant degree of resistance against challenge with 5000 non-irradiated metacercariae. The resistance was more pronounced in the group vaccinated with metacercariae irradiated at 3 krad.