Multivalent glycoconjugate vaccines

Antigenic multivalent molecular construct consisting of a basic unit comprising a helper-T dependent carrier protein covalently bound to a minimum of three carbohydrate structures which are capsular polysaccharides of different serological specificity by a linker comprising imine reduced bonds and amide bonds, wherein each carbohydrate structure comprises at least one of the repeating basic epitopes consisting of a minimum of five to twelve monosaccharide residues, where said carrier protein is selected from the group consisting of natural diphtheria mutant protein CRM197, diphtheria toxoid, tetanus toxoid, Protein D from Haemophilus influenzae, Pneumococcal surface proteins, Pneumococcal toxin and derivatives thereof including tetanus toxoid derivatized by an adipic acid dihydrazide spacer characterized in that at least one mole or fraction thereof of protein carrier carries at least one mole or fraction thereof of each of the at least three different type-specific carbohydrate antigens.