In 1881 Louis Pasteur demonstrated to an incredulous world the efficacy of his vaccine for the prevention of the fatal disease anthrax in sheep and cattle. A decade later Pasteur’s nephew and assistant, Adrien Loir, was manufacturing the vaccine in Sydney. But although Loir’s operations were begun at the behest of local pastoralists, the diffusion of the Pasteur vaccine was not very successful in Australia. Within a few years it was virtually displaced from the market by the modified vaccine produced by two Australian men, John Alexander Gunn and John McGarvie Smith. The process of transfer and diffusion involved in that displacement is the concern of this paper. In particular, it highlights the importance of local adaptation for the successful diffusion of anthrax vaccination in Australia.