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

Inclusion Criteria: * The subject is 2-3 months old (minimum 6 weeks old), 7 months old and above at the time of enrollment, and the legal guardian and/or the subject can provide legal identification certificate; * The subjects themselves and/or their legal guardians understand the vaccination and trial procedures, voluntarily participate in the trial and sign the informed consent form; * The subject and/or legal guardian can comply with the clinical trial protocol, have the ability to use thermometer, scale and fill in diary card and contact card as required; * Female subjects of childbearing potential agree to take effective contraceptive measures from enrollment to 6 months after vaccination. * For calibration group subjects: 18 to 55 years of age, ≥ 50 kg for males or ≥ 45 kg for females. Exclusion Criteria: * Axillary body temperature ≥ 37.3 ℃ on the day of enrollment; * History of infectious diseases caused by Streptococcus pneumoniae confirmed by bacterial culture within 3 years; * Have received or plan to receive a Streptococcus pneumoniae vaccine outside the trial protocol, including marketed or other investigational Streptococcus pneumoniae vaccines; * Pregnant or lactating women; Previous history of severe allergy to any vaccine or drug, such as urticaria, dyspnea, angioneurotic edema, anaphylactic shock, Henoch-Schonlein purpura, thrombocytopenic purpura; * Allergic to any component of the investigational vaccine; * Suffering from severe respiratory diseases (s…