The immune reponse to type III pneumococcal polysaccharide in mice with malaria.

The immune response of BALB/c mice to type III pneumococcal polysaccharide (SIII), as measured by splenic PFC, was abolished at the height of an acute self-limiting attack of malaria caused by the murine plasmodium P. yoelii, over a wide range of antigen doses. The response to antigen, given at various times after clinical recovery, gradually reappeared, but did not reach normal levels until 12 weeks after the injection of the parasite. A second injection of P. yoelii given 1 hr before SIII caused a moderate degree of depression, although in this case the plasmodium does not multiply. In chronic malaria the response to SIII was also very poor. Short term under-nourishment was found to reduce only slightly the response to SIII.