Efficacy of the EG95 hydatid vaccine in a macropodid host, the tammar wallaby

Abstract

SUMMARYIn Australia, macropodids are common intermediate hosts for the cestodeEchinococcus granulosus, and sylvatic transmission is maintained via wild dogs. The parasite causes mortality in a number of macropodid species and the sylvatic cycle provides a source of infection to domestic livestock and humans. We determined the efficacy of the hydatid vaccine, EG95 in the tammar wallaby,Macropus eugenii, challenging either 1 or 9 months post-vaccination. EG95 provides similar protection to that seen in sheep (96–100%). Control tammars were significantly more likely to become infected (odds ratio 29·44; CI 4·13, 209·97;P=0·001) and to develop more cysts (count ratio 26·69; CI 5·83, 122·19;P<0·001). The vaccination may be beneficial if administered pre-release in captive breeding programmes for endangered macropodids. Further work to develop oral delivery methods may enable vaccine administration of wild animals and thereby a reduction in sylvatic transmission.