Evaluation of Safety and Immunogenicity of Combined Immunization of sIPV, DTaP and HepA

Inclusion Criteria:

• Subjects must have participated the clinical trial titled "Clinic Trial to Evaluatethe Safety and Immunogenicity of Combined Immunization of sIPV and DTaP" (NCT04053010)in 2019, and have finished 3 doses of combined immunization of sIPV and DTaP;
• Subjects aged 18-19 months old at the date of recruitment;
• With informed consent form (ICF) signed by parent(s) or guardian(s);
• Parent(s) or guardian(s) are able to attend all planned clinical appointments andobey/follow all study instructions;
• Subjects have not been vaccinated with sIPV/DTaP/HepA at the age of 18-month-old yet;
• No less than 14 days since the last dose of vaccination;
• Axillary temperature ≤37.0℃.

Exclusion Criteria:

• With a medical history with hypersensitiveness, eclampsia, epilepsy, cerebropathia andneurological illness;
• Allergic to any ingredient of vaccine or with allergy history to any vaccine;
• Subjects with immunodeficency or suspected impairment of immunologic function (e.g.caused by HIV), or subjects are in the process of immunosuppressor therapy(Takingorally injecting of steroid hormone);
• Administration of immunoglobulins within 30 days prior to this study;
• Acute febrile disease(temperature ≥ 37.0°C) or infectious disease;
• With a clearly diagnosed history of thrombocytopenia or other coagulopathy, may causecontraindications for subcutaneous injection;
• With any serious chronic illness, acute infectious diseases, or respiratory diseases;
• With severe cardiovascular disease, liver and kidney diseases or diabetes mellituswith complications;
• With any kind of infectious, purulent, or allergic skin diseases;
• With any other factor that makes the investigator determines the subject is unsuitablefor this study.