Sharing of Cercarienhüllen Reaktion Antigens between Schistosoma Mansoni Cercariae and Adults and Uninfected Biomphalaria Pfeifferi *

Abstract
Cercarienhüllen Reactions (CHR) were obtained from baboons which were infected in the laboratory with Schistosoma mansoni, baboons which had had adult S. mansoni surgically introduced into their mesenteric veins, and rabbits which had been immunized with antigen prepared from uninfected Biomphalaria pfeifferi hepatopancreases. Attempts to ascertain the relationship between these antigens by absorption studies demonstrated that the CHR is due to a complex group of antigens, some of which are shared between the snail, cercaria, and adult, while others are shared between the snail and the cercaria or between the cercaria and the adult. The role of CHR antigens in the phenomenon of antigen sharing between life cycle stages of the parasite and between the parasite and its intermediate host may be a means of further elucidating the antigenic complexity of the CHR.