The invention provides a synthetic peptide sequence for use in the production of antibodies characterised in that said antibodies are cross-reactive with C. difficile toxin A and toxin B. The synthetic peptide sequence is preferably characterised in that the sequence comprises at least 4 consecutive amino acids from the N-terminus enzymatic domain and/or the central translocation domain of C. difficile toxins A and/or B. More particularly the sequence comprises at least 4 consecutive amino acids from amino acids 1-1843 of C. difficile toxin A and/or amino acids 1-1845 of C. difficile toxin B, preferably amino acids 1-1734 of C. difficile toxin B.
