Schistosome-specific antibody isotype levels in low and high antibody responders. Serum levels of schistosome-specific IgG, IgG1, IgG2, IgG3, IgG4, IgE, IgM, IgA were analysed by ELISA. Relative concentrations of antibody isotypes were compared between the high responders and low responders. NS, no significance. Open square bars represent mean of relative antibody concentration of low responders, black square bars represent mean of relative antibody concentration of high responders. Error bars represent SEMs.