Barbervax, a vaccine for Haemonchus contortus infection of sheep: attempts to extend the registration claim to include goats

Summary

Barber's Pole Worm (Haemonchus contortus) is an important parasite of goats and sheep in Australia and overseas. Control relies on anthelmintic drugs combined with pasture management, but strains of Haemonchus resistant to these drugs are common and widespread. Compared to sheep producers, goat farmers have relatively few options to control gastrointestinal nematode parasites because many anthelmintics are registered for sheep only.

Barbervax, a vaccine for Barber's Pole Worm, has recently been registered for use in Australian sheep. Preliminary and on-going trials overseas suggest that Barbervax could work in goats.

Three efficacy field trials with kids were performed in the Northern Tablelands of NSW with a view to obtaining caprine registration in Australia. Unfortunately the results were mixed: one trial worked well, a second showed some positive effects, but a third failed. Because the anti-vaccine antibody responses were similar in all three trials, the underlying cause of the variable vaccine efficacy is not understood.

It was concluded that the results were too variable for registration to be granted by the regulators.