A Clinical Trial to Evaluate the Safety and Immunogenicity of PPV23 Vaccine Revaccinated in 60-70 Years Old

Inclusion Criteria:

1. The age was 60-70 years old on the day of enrollment;
2. The subjects have signed the informed consent and signed the date;
3. The subjects are able to participate in all planned follow-up visits and were able to follow all trial procedures (e.g. complete diary card / contact card, return to visit);
4. The subjects in the study group had been vaccinated with 23 valent pneumococcal polysaccharide vaccine made in China for more than 5 years;
5. The control group had never been vaccinated with any pneumococcal vaccine; 6.Axillary temperature ≤37.0℃.

Exclusion Criteria:

1. With a medical history with hypersensitiveness, eclampsia, epilepsy, cerebropathia and neurological illness;
2. Allergic to any ingredient of vaccine or with allergy history to any vaccine; 3.Subjects with immunodeficency or suspected impairment of immunologic function (e.g. caused by HIV), or subjects are in the process of immunosuppressor therapy(Taking orally injecting of steroid hormone);

4.Administration of immunoglobulins within 30 days prior to this study; 5.Acute febrile disease(temperature ≥ 37.0°C) or infectious disease; 6.With a clearly diagnosed history of thrombocytopenia or other coagulopathy, may cause contraindications for subcutaneous injection; 7.With any serious chronic illness, acute infectious diseases, or respiratory diseases; 8.Suffering from serious cardiovascular diseases (pulmonary heart disease, pulmonary edema, hypertension can not be controlled to normal by drugs), liver and kidney diseases, diabetes with complications; 9.With any kind of infectious, purulent, or allergic skin diseases; 10.With any other factor that makes the investigator determines the subject is unsuitable for this study.