The antigenicity or immunogenicity of the polypeptides according to the invention can be assessed by usual immunization experiments, using, e.g., rodents such as mice or rabbits as the immunized animal, or using assays, e.g. ELISA, with polyclonal or monoclonal antibodies raised in advance against B. burgdorferi or an immunogenic B. burgdorferi-related protein or polypeptide.