Immuno-epidemiological studies that use a treatment/re-infection study design - in which immune mediators are measured, a cohort treated and their re-infection levels determined 1 to 2-yr later - have shown IgE levels, specific for schistosome adult worm derived antigens (SWA), to be a major correlate of immunity to infection with each of the 3 schistosome species that cause most human schistosomiasis [2], [3], [4]. This evidence concerns the gene IGHE and infection.