Phase I/II Clinical Trial of 26-valent Pneumococcal Conjugate Vaccine

As an experimental group. The active ingredient of 26-valent pneumococcal conjugate vaccine is the capsular polysaccharide of 26 pneumococcal serotypes conjugated to the tetanus toxoid carrier protein. Administer one dose of 0.5mL each time.

As a control group. The effective ingredients of 23-valent pneumococcal polysaccharide vaccine are 23 serotypes of pneumococcal capsular polysaccharides. Administer one dose of 0.5mL each time.

As a control group. The active ingredient of 13-valent pneumococcal conjugate vaccine is the capsular polysaccharide of 13 pneumococcal serotypes conjugated to the tetanus toxoid carrier protein. Administer one dose of 0.5mL each time.