Vaccination of bovines against Echinococcus granulosus (cystic echinococcosis)

Abstract

Hydatid disease is an important human zoonosis. Humans become infected from carnivores that are infected with the Echinococcus granulosus tapeworm. Carnivores become infected after consuming hydatid cysts from grazing animals, which are generally sheep, goats and cattle. A vaccine, known as EG95, can protect sheep and goats against cystic echinococcosis. This paper describes the adaptation of the EG95 vaccine for use in cattle. The monitoring of results used serology and also infection with E. granulosus eggs, followed by necropsy. Immunisation with living E. granulosus oncospheres showed that cattle could be immunised against E. granulosus. Immunisation of cattle with EG95 plus QuilA was also successful. A dose-response and adjuvant trial showed best results were achieved with 250 μg of antigen and 5mg of the adjuvant QuilA, which was 5 times the recommended sheep dose. After two vaccinations given one month apart, 90% protection was maintained for 12 months. At 12 months a third vaccination boosted protection to 99% which was maintained for a further 11 months.