The immune-dependence of schistosomicidal chemotherapy: relative lack of efficacy of an antimonial in Schistosoma mansoni-infected mice deprived of their T-cells and the demonstration of drug-antiserum synergy.

When T-cell deprived CBA mice, infected with Schistosoma mansoni, were treated orally with potassium antimony tartrate, the reduction in size of their worm burdens was less than in similarly treated, immunologically-intact animals. The defect in deprived mice could be restored by the administration of serum obtained from S. mansoni-infected normal mice simultaneously with the drug, but by a different route. A serum component, probably immunoglobulin, obtained from rabbits which had been injected with an extract from S. mansoni adult worms was also found to act synergystically with the antimonial in the chemotherapeutic eradication of S. mansoni worms from immunologically intact mice.