STUDIES ON HETEROLOGUOUS IMMUNITY IN SCHISTOSOMIASIS .2. HETEROLOGOUS SCHISTOSOME IMMUNITY IN RHESUS MONKEYS

  • 1 January 1968
    • journal article
    • research article
    • Vol. 38  (1) , 19-+
Abstract
Previous studies on heterologous immunity in mice indicated that Schistosoma bovis and S. mattheei could be used to limit the severity of infection resulting from subse-quent challenge by S. mansoni. These observations were extended to study the immunizing effect in rhesus monkeys of both S. mattheei and S. bovis. The bovine schistosomes were relatively non-pathogenic in rhesus monkeys. Immunization with 1000-2000 cercariae resulted in a marked reduction in the pathogenic effect of subsequent challenge with S. mansoni. This effect was demonstrated by a decrease in the worm load and tissue egg densities in 10 immunized monkeys as compared with 5 control animals. There was no correlation between fluorescent antibody titers and the intensity of infection or the degree of acquired immunity. There was a cross-reaction between S. mansoni and the bovine schistosomes. Natural heterologous immunity (zooprophylaxis) may be of considerable epidemiological importance in determining the severity of schistosomiasis in man.