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

In Australia, macropodids are common intermediate hosts for the cestode Echinococcus 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.