[Influence of reintervention by the bacillus of Calmette and Guérin (BCG) on the nonspecific resistance of the mouse to Schistosoma mansoni (author's transl)].

Significant resistance to Schistosoma mansoni appears in mice two weeks after treatment with BCG. The state of nonspecific resistance is considerably increased if the injection of BCG two weeks prior to the infestation test is carried out using mice who have already received BCG. Thus, BCG innoculation in an organism presentized to the bacillus antigens increases immunostimulation. According to these results, during primoinnoculation with BCG, immunostimulation is not significant before this second week, that is, the time necessary for a state of hypersensitivity to appear. Nevertheless, it should be noted that weak yet detectable immunostimulation can be observed before the 14th day following a BCG primoinfection. Thus, the possible role of other mechanisms should be considered.