Vaccination trials in Australia and Argentina confirm the effectiveness ofthe EG95 hydatid vaccine in sheep

Experimental vaccine trials against hydatid disease have been undertaken in sheep using the EG95 recombinant vaccine. Challenge infection was with via ble Echinococcus granulosus eggs obtained from a New Zealand isolate (dog/s heep cycle), an Australian isolate (dingo/wallaby cycle) and an Argentine i solate (dog/sheep cycle). Vaccination with EG95 conferred a high degree of protection against challenge with all three parasite isolates (protection r ange 96-100%). Taken together, the trials demonstrated that 86% of vaccinat ed sheep were completely free of viable hydatid cysts when examined approxi mately 1 year after challenge infection. Vaccination reduced the number of viable cysts by 99.3% compared with unvaccinated controls. These results su ggest that the EG95 vaccine could have wide applicability as a new tool for use in hydatid control campaigns. (C) 1999 Australian Society for Parasito logy Inc. Published by Elsevier Science Ltd. All rights reserved.