Inclusion Criteria:
1. Healthy children aged 2 to 5 years with stable health status
2. Participants and their legal representative provide legal proof of identity, as well as vaccination record
3. Participants' legal representative understand and voluntarily sign the informed consent form
4. Willing and able to comply with all scheduled visits, sample collection, vaccination and other study procedures, and maintain accessible contact throughout the study period.
Exclusion Criteria:
1. Received any pneumococcal vaccine prior to enrollment
2. History of invasive pneumococcal diseases or other pneumococcal diseases caused by Streptococcus pneumoniae, as confirmed by laboratory tests
3. History of allergy or adverse reactions to the vaccine or vaccine components, or history of allergy, such as urticaria, dyspnea, angioedema and anaphylactic shock
4. History of severe diseases judged by the investigator to interfere with vaccination, including but not limited to cardiovascular and cerebrovascular diseases (e.g., complicated or complex congenital heart disease), hematological diseases (e.g., severe anemia), liver and renal diseases, digestive system diseases, respiratory diseases (e.g., active pulmonary tuberculosis), malignant tumors, history of major solid organ transplantation, etc.
5. Autoimmune diseases or immunodeficiency diseases (including but not limited to systemic lupus erythematosus, rheumatoid arthritis, autoimmune thyroid disease, asplenia, functional asplenia, HIV infection)
6. Abnormal coagulation functions (e.g., coagulation factor deficiency, blood coagulation diseases, platelet disorders)
7. Have/have suffered from a serious neurological disorder (epilepsy , convulsions or seizures) or mental illness or have a family history of such diseases
8. Have received \> 14 days of corticosteroids or other immunomodulatory therapy in the past 6 months(defined as ≥2 mg/kg per day with a maximum daily dose of no less than 20 mg prednisone equivalent, or equivalent dosage), or cytotoxic therapy, or plan to receive such therapy during the study period (inhaled, intranasal or topical corticosteroids are excluded)
9. Received immunoglobulin or other blood products within 3 months prior to enrollment, or plan to receive such treatment during the study period
10. .Received other investigational drugs or vaccines within 30 days prior to enrollment, or plan to receive such drugs or vaccines during the study
11. Received live attenuated vaccine within 14 days prior to enrollment
12. Received subunit or inactivated or other vaccine within 7 days prior to enrollment
13. Acute diseases or acute onset of chronic diseases within 7 days prior to enrollment, or known or suspected active infection
14. Had fever (axillary temperature\> 37.0℃) prior to administration on the scheduled study vaccination day
15. In the investigator's judgment, the participant has any other factors that make him or her unfit to participate in the clinical trial
