To provide novel vaccines capable of providing appropriate protection against serotype 10A, 22F or 33F Streptococcus pneumoniae, and methods for producing the vaccines.SOLUTION: Disclosed is a method for preparing an immunogenic conjugate comprising S. pneumoniae serotype 10A polysaccharide covalently linked to a carrier protein. An isolated serotype 10A capsular polysaccharide is reacted with 0.1-0.3 mole equivalent of periodate, and then 0.5-2 mole equivalent of a reaction quencher is added to obtain an activated S. pneumoniae serotype 10A polysaccharide of which degree of oxidation is in a range of 8-14. The activated serotype 10A polysaccharide is mixed with a carrier protein and reacted with a reducing agent to form a conjugate.SELECTED DRAWING: None【課題】血清型10A、22F又は33F肺炎連鎖球菌(Streptococcus pneumoniae)を適切に防御可能な新規肺炎連鎖球菌ワクチン、及び前記ワクチンの製造方法の提供。【解決手段】担体タンパク質に共有結合で連結された肺炎連鎖球菌血清型10A多糖を含む免疫原性コンジュゲートを調製するための方法。血清型10A莢膜多糖単離物を、0.1~0.3モル当量のペルヨーデートと反応させる。0.5~2モル当量の反応停止剤を加え、多糖の酸化度が8~14の間である活性化肺炎連鎖球菌血清型10A多糖を得る。前記活性化血清型10A多糖と担体タンパク質を混和し、還元剤と反応させてコンジュゲートを形成する。【選択図】なし