Objective To evaluate the stability for bulks of typhoid Vi polysaccharide protein conjugate vaccine, and provide supportive data in preparation and storage of the bulks.Methods Three batches of bulks for typhoid Vi polysaccharide protein conjugate vaccine were selected, stored at three different conditions,(37±2) ℃,(25±2) ℃ and 2-8 ℃,and sampling and detecting were performed periodically, including the main indexes of bulks such as polysaccharide con-tent, conjugated polysaccharide, molecular weight and id...