The present application discloses an immunogenic composition comprising a Hib saccharide conjugate and at least two further bacterial saccharide conjugates wherein the Hib conjugate is present in a lower saccharide dose than the mean saccharide dose of all the at least two further bacterial saccharide conjugates.本申請案揭示一種免疫原組合物,其包括至少2種不同腦膜炎雙球菌莢膜糖,其中一或多種係選自由MenA、MenC、MenY及MenW組成之第一群,其係藉助連接體結合至載體蛋白,以及一或多種不同糖,該糖係選自由MenA、MenC、MenY及MenW組成之第二群且係直接結合至載體蛋白。