The concept of using genetically modified infectious agents to deliver antigens to wildlife is not new. Recombinant vaccinia virus expressing rabies glycoprotein delivered in baits to wild foxes has proved to be a highly effective strategy to combat rabies [5] . Since then other vaccines developed against diseases of wildlife include a rabies virus based vector used to immunise wildlife against SARS [6] . Extension of this concept has seen recombinant viruses developed to control a host's biological processes. An example is recombinant viruses expressing zona pellucida antigen that successfully deliver immunocontraception to pest animal species in laboratory trials [7, 8] .