13-Valent Pneumococcal Polysaccharide Conjugate Vaccine(Sinovac Life Sciences)

Primary objective: To evaluate the safety of the test vaccine in subjects of each age group. Secondary objectives: (1) To evaluate the safety of the test vaccine in subjects of each age group; (2) To evaluate the immune response induced against all serotypes in subjects aged 2 months (minimum 6 weeks) 30 days after primary immunization with the test vaccine; (3) To evaluate the immune response induced against all serotypes in subjects aged 2 months (minimum 6 weeks) 30 days after booster immunization with the test vaccine; (4) To evaluate the immune response induced against all serotypes in subjects aged 2 to 5 years (before the 6th birthday) 30 days after immunization with the test vaccine.