The group aged 18-59 years old, the group ≥60 years old, and the group aged 2-17 years old were successively assigned to the group. Subjects in each age group were randomly vaccinated with 1 dose of experimental vaccine or control vaccine in a ratio of 1:1, with 48 people in each group receiving each dose. After the safety assessment was conducted on the 8th day after the first dose, the next age group could be enrolled only if the preliminary safety assessment results met the protocol requirements. When each age group is enrolled, laboratory index screening can be conducted 3 days in advance (the validity period of laboratory index detection results is 3 days). The progression of age groups is as follows:

Group 18-59 years old (48 people: 1 dose) → Group ≥60 years old (48 people: 1 dose) → Group 2-17 years old (48 people: 1 dose)

Safety observation: All subjects were observed on site for 30 minutes after vaccination, abnormal laboratory indicators (blood biochemistry, blood routine) of all subjects were observed on day 4 after vaccination, and adverse events of all subjects within 0-7 days were actively followed up by the researchers, and subjects were instructed to record the body temperature measured every day and adverse events (if they occurred) in the diary card. All subjects continued to observe adverse events within 8-28 days and made relevant records. All subjects were required to continue follow-up for SAE status up to 6 months after basic immunization.

Immunogenicity observation: Blood samples were collected before and 28 days after vaccination, and serum antibodies were detected by ELISA.

Inclusion Criteria:

• ≥2 years old healthy population;
• Subjects and/or guardians or trustees voluntarily signed informed consent forms and could comply with the requirements of the clinical trial protocol;
• Had not received any pneumonia vaccine in the last 5 years；
• Note: Healthy people do not include the following conditions: ① congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc.; ② History of epilepsy and mental illness; ③ Patients with congenital or acquired immunodeficiency, HIV infection, lymphoma, leukemia, systemic lupus erythematosus (SLE), juvenile rheumatoid arthritis (JRA), or other autoimmune diseases; Have been diagnosed with congenital or acquired immunodeficiency, HIV infection, lymphoma, leukemia, or other autoimmune diseases; ⑤ serious liver and kidney diseases, malignant tumors, all kinds of acute diseases or in the acute phase of chronic disease; Adults have diabetes, severe cardiovascular disease, and high blood pressure (systolic blood pressure ≥140mmHg or diastolic blood pressure ≥90mmHg) that cannot be controlled by medication.

Exclusion Criteria:

• Armpit temperature >37.0℃ before inoculation;
• Family history of seizures or convulsions, epilepsy, and mental illness;
• People with a progressive neurological disorder or a history of Guillain-Barre syndrome;
• The patients with clinically significant abnormalities in blood biochemistry and routine blood tests were tested before vaccination；
• People who received immunoenhancement or suppressant therapy within 3 months (continuous oral or intravenous infusion for more than 14 days);
• History of abnormal coagulation function (such as deficiency of coagulation factor, coagulation disease);
• Primary and secondary immunocompromised individuals (thyroid, pancreas, liver, spleen excision history, or need treatment for thyroid disease within the last 12 months);
• History of severe allergic reactions to vaccinations;
• Allergy to any component of the investigational vaccine;
• Have received live attenuated vaccine within 14 days; Other vaccines received within 7 days;
• Participating in or planning to participate in other clinical trials;
• Women of childbearing age are lactating, pregnant or planning to become pregnant in the near future;
• The investigator determined that other conditions were not suitable for participation in the clinical trial.