Patent ID: 8883172

Claim:
A composition comprising a cross-linked bacterial peptide, wherein the cross-linked bacterial peptide is derived from a non-toxic bacterial peptide treated with formaldehyde over a period of less than 144 hours in a reaction mix at a ratio (formaldehyde: reaction mix) of less than 2% (v/v or w/v) to introduce intra-molecular cross-linking into the non-toxic bacterial peptide, wherein the non-toxic bacterial peptide is selected from the group consisting of: (i) a non-toxic fragment of clostridial neurotoxin, wherein said non-toxic fragment is LH N , (ii) a non-toxic fragment comprising at least 200 contiguous amino acid residues of a Clostridium difficile toxin peptide, and (iii) a non-toxic Clostridium difficile surface peptide; and wherein the cross-linked bacterial peptide has enhanced efficacy for inducing a protective immune response as compared to the untreated non-toxic bacterial peptide from which it is derived.