CHEMOTHERAPY ACCELERATES THE DEVELOPMENT OF ACQUIRED IMMUNE-RESPONSESTO SCHISTOSOMA-HAEMATOBIUM INFECTION

Treatment of 41 Schistosoma haematobium-infected children, 5-16 years old, with the drug praziquantel induced a switch from a predominantly IgA-specific antibody response to a predominantly IgG1 response within 12 weeks. A cross-sectional survey suggests that the same switch occu rs naturally, but over several years, as children age (n = 251), The s witch may be driven by alterations in cytokine levels in response to t he release of antigens by dead or damaged parasites. Adults are more r esistant to schistosome infection than children, and the switch to an ''adult'' response suggests that praziquantel treatment may have an im munizing effect, with benefits extending beyond a transient reduction in levels of infection.