Vaccination would be preferred to leptospirosis control measures. However, current vaccines are heat killed whole-cell bacterins that generate serovar specific protection and several side effects. Modern molecular assays have revealed antigens that may replace traditional whole-cell vaccines. Among these, LigB protein is surface-exposed outer membrane protein of virulent leptospires and therefore potential target of a protective immune response. Some unsuccessful attempts at using these antigens as vaccines have been reported. However, we believe that immune modulation through alternative adjuvants and co-adjuvants may overcome previous setbacks. In this light, our study aimed to evaluate the protective immune response in hamsters vaccinated with 40 µg of rLigBNI using oil adjuvant (OA), with or without green propolis (GP) as co-adjuvant. Upon a challenge, all groups immunized with rLigBNI, coupled or not with GP, were highly immunogenic and revealed statistically significant (p<0.05) protection of hamsters from lethal leptospirosis. Additional studies are being carried out to assess the optimum dose, protection against heterologous challenge, and vaccine dynamics.