The present invention relates to a polypeptide comprising a mutant fragment of an outer surface protein A (OspA) with the amino acid sequence of SEQ ID NO: 190 or any functional variant of said amino acid sequence, a nucleic acid coding the same, a vector or host cell comprsing the same, a method of producing the cell or protein, a pharmaceutical composition (particularly a vaccine) comprising the polypeptide and/or the nucleic acid and the polypeptide or pharmaceutical composition for use as a medicament, particularly as a vaccine, or for use in a method of treating or preventing a Borrelia infection.
