Geometric means of the bone marrow parasite loads over the course of the study. The bone marrow parasite loads were assessed by quantitative PCR targeting a 200 bp fragment of the kinetoplast DNA performed on weeks 58 (immediately before the challenge, but one year after the last vaccination), 73, 81, 90, 98 and 105 (equivalent to 47 weeks after the challenge). The number of parasites per ml of bone marrow could thus be calculated, and the results are presented as the geometric mean of the number of parasites per ml bone marrow for each group. Samples were considered as negative if the parasite load was inferior to 40 parasites per ml bone marrow. Error bars represent the SD. *p = 0.026.