Although beneficial effects of trained immunity on leptospirosis have been reported through host-directed treatment using a TLR2/NOD2 agonist (CL429) [132] and proposed as an adjuvant to increase the efficiency of leptospiral vaccines, deeper studies are needed to characterize the type of immune modulation induced by rBCG expressing leptospiral antigens. This evidence concerns the gene NOD2 and leptospirosis.