Method for preparing conjugates of carbohydrate-glycopeptide multiple antigen

A method for preparing a conjugate of T cell epitope containing carbohydrate of formula (I): M (TB) n (I) wherein: - M is a polylysine dendrimer core; - T is a T cell epitope; - B is a B-cell epitope containing carbohydrate comprising at least one carbohydrate moiety (b); - n is an integer and represents the number of groups covalently bonded to M -TB; said method comprising the steps of: i) coupling a B-cell epitope containing protected carbohydrates (BPR), the hydroxyl groups of the carbohydrate moiety (b) are protected with a protecting group (Pr), with a compound M (T) n, thereby forming a conjugate T cell epitope containing carbohydrates M (T-BPR) n, selecting said protecting group (Pr) from the group consisting of allyl, p-methoxybenzyl (PMB), t-butyldimethylsilyl (TBDMS) benzyloxymethyl (BOM), levulinyl (Lev), benzoyl (Bz), 2,5-difluorobenzoyl, chloroacetyl, benzyl (Bn) or an acetyl (Ac), or forming, with the two hydroxyl groups to which is attached a isopropylidene ketal C5-C6 alkylcarbonate or a cyclic C5-C6; and ii) removing the protecting grups Pr conjugate M (T-BPR) n obtained, thereby obtaining the conjugate of T cell epitope containing carbohydrates M (TB) n.