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.本申請案揭示一種包含至少2種不同腦膜炎雙球菌(N.meningitidis)莢膜糖之免疫原組合物,其中一或多種係選自由MenA、MenC、MenY及MenW組成之第一群且其與蛋白質載體結合,其中糖:蛋白質比(W/W)係介於1:2-1:5之間,及一或多種不同糖係選自由MenA、MenC、MenY及MenW組成之第二群且其與蛋白質載體結合,其中糖:蛋白質比(w/w)係介於5:1-1:1.99之間。