A Phase 3 Study to Evaluate the Immunogenicity and Safety of Walvax's PCV13-TT as Compared to Pfizer's PCV13

Inclusion Criteria: Infants must meet ALL the following inclusion criteria for enrollment in the study, at the time of the screening: Healthy infants based on medical history and clinical assessment. Age of 6-8 weeks at enrolment. Infants will be eligible since the day they reach 6 weeks of age and until 8 weeks of age included. Body weight at enrollment ≥3.5 kg. Infant's parent(s) or legal guardian(s) must be able and willing to provide voluntary written/thumb-printed informed consent for the infant to participate in the study. Infant's parent(s) or legal guardian(s) must be able to comprehend and comply with study requirements and procedures and must be willing and able to return or make themselves available for all scheduled follow-up visits. Infant's parents must have a readily identifiable place of residence in the study area, be available for the duration of trial participation, and have means of telephone contact. Exclusion Criteria: The following criteria should be checked at the time of study entry. If ANY exclusion criterion applies, the subject must not be included in the study: Use of any investigational medicinal product prior to randomization or planned use of such a product during the period of study participation. History of S. pneumoniae infection as confirmed by medical enquiry or as confirmed by laboratory testing if available. Participant has fever (axillary temperature ≥ 37.5℃) within 24 hours prior to the 1st dose of vaccination; (If the subject does not meet the criteria, the visit may be rescheduled when the criteria are met.) The infant who are children in care, preterm and low-birth-weight(Preterm infants have a gestational age below 37 weeks at birth and low-birth-weight infants have a birth weight below 2.5 kg). History of allergic disease or history of a serious reaction to any prior vaccination or known hypersensitivity to any component of the 2 study vaccines. This includes all components of the EPI vaccines. History of anaphylactic shock. Any abnormal vital sign. Any moderate or severe acute illness. History of administration of a non-study vaccine within 30 days prior to administration of study vaccine, other than EPI vaccinations (Note: EPI vaccines other than that stipulated in the study must be given at least 14 days prior to the investigational vaccine.) Individuals who receive treatment with radiotherapy or immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids (if systemic corticosteroids are administered for 14 days at a dose of 20 mg/day of prednisone or equivalent), e.g., for cancer or an autoimmune disease, or planned receipt throughout the study. Inhaled/nebulized, intra-articular, epidural, or topical (skin or eyes) corticosteroids within indicated dosage are permitted. Administration of immunoglobulins and/or any blood products or anticipation of such administration during the study period. History of known disturbance of coagulation or blood disorder that could cause anemia or excess bleeding (e.g., thalassemia, coagulation factor deficiencies, severe anemia at birth). History of suspected primary immunodeficiency. History of meningitis, seizures or any neurological disorder. A family history of congenital or hereditary immunodeficiency. The infant is a direct descendant (child or grandchild) of any person employed by the Sponsor, the CRO, the investigator, study site personnel. Any medical or social condition that in the opinion of the investigator may compromise the well-being of the study participant, interfere with the study objectives, pose a risk to the study participant, or prevent the study participant from completing the study follow-up.