 Methodology : Phase III trial, self-contained, randomized, double blind, in two parallel groups receiving 3 injections at D0, W4, W8 and a boost at W52, one group receiving Bilhvax, the other one placebo, in S. haematobium infected children pretreated by two doses of PZQ at W9 and W8 Patient included : Infected school children, 6 to 9 years of age. 