The need for vaccination against schistosomiasis is an achievable goal. In this work the protective and antifi-brotic effect of 74 KDa schistosoma protein antigen recognized by protec‌tive monoclonal antibody was evaluat‌ed histologically and immunohisto-chemicalty. Swiss mice were immunized with 50 mg of purified 74KDa antigen without and with Freund's adjuvant. Then mice were infected with 200 S. mansoni cercari-ae three days after final immunization. The results revealed a protection level of 76.6% and 80% was obtained us‌ing the 50mg antigen without and with Freund's adjuvant. Histological ex-amination showed marked decrease
of the grnuloma number and size and marked reduction of both collagen and reticular fibers around granulo-mas of mice liver .Immunohisto-chemical study revealed decrease of the intensity or even absent of the schistosomal antigen in immunized liver compared to that infected and not immunized.
From this work it can be concluded that in addition of the ability of the 74KDa antigen to mediate protection against schistosoma mansoni infec‌tion. It can reduce the granulomatous reaction around eggs lodged in the liver by its ability to modulate the im-mune system of the infected host. So the protection conferred by the 74