This study is an open phase Ⅳ clinical trial to evaluate the immunity persistence after single dose of 23-valent pneumococcal polysaccharide vaccine.The experimental vaccine was manufactured by Sinovac Biotech Co., Ltd,the control vaccine was manufactured by Chengdu Institute of Biological products Co., Ltd..A total of 600 subjects including 450 subjects in the experimental group and 150 subjects in the control group who participated in the second stage of phase Ⅲ clinical trial (PPS)will be enrolled .Based on the age at the time of enrollment in the phase Ⅲ study, there will be 150 participants in each age group (2-17 years old group, 18-60 years old group and ≥61 years old) in the experimental group and 50 participants in each age group in the control group .3.0-3.5ml of venous blood will be collected from all subjects after enrollment.
This an open phase Ⅳ clinical trial of 23-valent pneumococcal polysaccharide vaccine manufactured by Sinovac Biotech Co., Ltd.The purpose of this study is to evaluate the immunity persistence after single dose of 23-valent pneumococcal polysaccharide vaccine.