A specific antibody against a compound of formula (I) wherein X is O, NH, S, CH2; L is a linker that is a divalent spacer; A is an adjuvant or carrier that is an immunogenic molecule or an immunogenic particle; and wherein bonds between linker and saccharide moiety and between linker and carrier are of covalent type; wherein the linker L presents a chemical structure suitable to space the saccharide moiety and the carrier by 7-30 atoms when the adjuvant/carrier A is a biomacromolecule or by 19-30 atoms when the adjuvant/carrier A is a metallic nanoparticle; wherein the carrier/adjuvant A can be selected among a macromolecule, a macrocycle, a dendrimer, a liposome, a nanoparticle, an oligosaccharide featuring from two to five monosaccharidic units or cells like dendritic cells.