At the moment the only vaccine registered for use in Australia for ovine Johne’s disease is the Gudair vaccine (Zoetis). Members of our team were responsible for the scientific validation of this vaccine in Australia, leading to its registration, and it has been widely used as a control measure. A similar vaccine, Silirum (Zoetis),  has recently been registered for cattle. While Gudair vaccine can reduce disease by up to 90%, sheep can still become infected, and some shed large numbers of bacteria in their faeces, meaning that they are infectious (Reddacliff et al 2006). Operator safety is also an issue when animals are being vaccinated because the vaccine is highly irritant if accidentally injected (Windsor et al 2005). To address these issues we are developing a safer, more effective vaccine to protect both sheep and cattle against Johne’s disease. Johne’s vaccines also cause animals to react undesirably in tests for bovine tuberculosis, so a further research goal is to find a way around this problem.


 October 2014