Immunity in human schistosomiasis.

Field studies on immunity in human schistosomiasis are expensive, labour-intensive and extremely time-consuming, requiring many years to yield even provisional results. In this review, Anthony Butterworth and Paul Hagan summarize the need for such studies, the evidence for immunity in man, the immunological factors that may govern the expression of immunity, and the implications of such work for the development of new methods of control through vaccination.