A vaccine for schistosomiasis: Alternative approaches

An independent trial of candidate antigens for a Schistosoma mansoni vaccine has been completed recently under the auspices of the World Health Organization TDX programme. It has been acknowledged that the results of the trial failed to meet expectations and, therefore, it is appropriate that the options for future work should be considered. In this article, Mike Doenhoff describes two S. mansoni molecules - a schistosome larval protease and a high molecular weight egg and worm antigen. Both are associated with protective immunity, but they have unusual immunological properties that distinguish them from the antigens tested so far. The results suggest that alternative approaches to a schistosomiasis vaccine are still worth exploring.