The present invention relates to a liposome composition including liposomes encapsulated with a pneumococcal capsular polysaccharide antigen, a method of preparing the composition, and a usage of the composition as a pneumonia vaccine, wherein the liposome composition comprises: a phospholipid selected from phosphatidylcholine and phosphatidylethanolamine and a cholesterol or derivative thereof selected from cholesterol and cholesterol hemisuccinate, wherein the liposome does not include a carrier protein.
