Chimera proteins including: (i) at least one sequence of a VlsE protein of a Borrelia species selected from B. garinii, B. burgdorferi sensu stricto and B. afzelii, and (ii) at least one sequence including sequences of the IR6 domain of B. burgdorferi sensu stricto, B. afzelii and B. garinii. Also, a method and a kit for the in vitro diagnosis of Lyme borreliosis using said proteins.