Several years have elapsed since the publication by Johnson et al. (1989) of the cloning of a recombinant antigen from the cestode parasite Taenia ovis which stimulated high levels of protective immunity in sheep. A great deal of subsequent research and development was necessary to bring the fledgling vaccine to the point of being a registered commercial product. The results of these subsequent studies are dealt with briefly in this paper, including the results of field trials. The T. ovis vaccine was registered by the New Zealand Animal Remedies Board in February 1994. Where then is the commercial product ? This paper gives a background to market problems which have emerged through the politics (and realities) of the NZ T. ovis control campaign. It serves as notice that the best science dedicated to producing vaccines or products for parasitic, or other, diseases often faces significant hurdles in the real world of commerce and politics.
