A Phase III clinical trial of 13-valent pneumococcal conjugate vaccine (PCV13)developed by Sinovac Life Science Co., Ltd will be conducted in infants aged approximately 2 months (42 to 89 days).

The objective of the study is to evaluate the immunogenicity and safety of Sinovac PCV13. The trial is a randomized, double-blind, active controlled phase III clinical trial.

A phase III clinical trial of the study of 13-valent Pneumococcal Polysaccharide Conjugate Vaccine (PCV13) developed by Sinovac Life Science Co., Ltd (Sinovac) will be conducted in Philippines infants aged approximately 2 months (42 to 89 days).

The trial is a randomized, double-blind, active controlled study. The objective of this study is to evaluate the immunogenicity and safety of PCV13 manufactured by Sinovac Life Science Co., Ltd. The active control vaccine is Prevenar 13™ manufactured by Pfizer.

About 500 infants aged approximately 2 months (42 to 89 days) will be enrolled. Participants will be randomized in 1:1 ratio to the test group and control group.

Inclusion Criteria:

1. Health infants aged approximately 2 months (42 to 89 days)
2. Have a parent/legal guardian who has provided written informed consent after being fully informed about the study.
3. Be able to provide the vaccination records since birth.
4. The infant's mother is tested negative for HIV, syphilis, hepatitis B, and hepatitis C before the infant's enrollment to this study (test results obtained during pregnancy are acceptable, if provided).

Exclusion Criteria:

1. Previous vaccination of any licensed or investigational pneumococcal vaccine, or planned receipt during the study participation;
2. Previous vaccination of vaccines containing the component of diphtheria, tetanus, pertussis, poliomyelitis, and/or Hib vaccine.
3. Previous receipt of ≥2 doses of hepatitis B vaccine; or receipt of a single hepatitis B vaccine dose administered at >30 days old.
4. History of severe adverse reaction to previous vaccinations and/or serious allergic reactions (eg, anaphylaxis) to any vaccine component.
5. History of any laboratory confirmed pneumococcal bacterial pneumonia or invasive pneumococcal diseases caused by S pneumoniae.
6. Premature infants (born before week 37 of gestation).
7. Severe congenital malformations, developmental disorders, clinically significant genetic defects, malnutrition.
8. Autoimmune diseases or immunodeficiency/immunosuppression.
9. Serious chronic diseases such as Down's syndrome, diabetes, sickle cell anemia, or neurological disorders.
10. Abnormal coagulation functions (e.g., coagulation factor deficiency, blood coagulation diseases, platelet disorders).
11. Received immunosuppressive for ≥14 days (e.g., prednisone equivalent of ≥2 mg/kg), or cytotoxic drug before enrollment, or plans to receive these treatments during the study participation.
12. Received blood products before investigational vaccine inoculation, or plan to receive these treatments during study participation.
13. Received other investigational drugs/vaccines before enrollment, or plan to receive investigational drugs/vaccines during study participation.
14. Received live attenuated vaccines or nucleic-acid vaccines within 14 days before enrollment.
15. Received subunit or inactivated vaccines within 7 days before enrollment.
16. Acute diseases or acute exacerbations of chronic diseases within 7 days before enrollment.
17. Axillary temperature ≥ 37.5°C before enrollment.
18. Any other factors judged by the investigators as unsuitable for participation.