The purpose of this study is to evaluate the lot consistency, immunogenicity and safety of three lots of Sabin strain inactivated polio vaccine (Vero Cell) (sIPV) manufactured at commercial scale by Sinovac Biotech Co., Ltd., and evaluate the non-inferiority of investigational vaccine against a post-market inactivated polio vaccine.

This study is a randomized, double-blinded, and positive-controlled clinical trial. A total of 1300 infants aged 2 months will be enrolled and assigned to 4 groups in a ratio of 1:1:1:1 to receive vaccination of 3 lots of investigational sIPV and control IPV manufactured by Sanofi Pasteur S.A respectively. Each subjects should finish the three-doses primary vaccination at the schedule of 2,3,4 months of age. Thirty-days safety observation after each dose of vaccination will be carried out. Venous blood should be collected from all the subjects before and 30 days after the three-doses primary vaccination, for the neutralizing antibody assay, and further to evaluate the immunogenicity.

Inclusion Criteria:

• Healthy infants aged 60-89 days;
• legal identity;
• Informed consent form has been signed by guardians.

Exclusion Criteria:

• Vaccination history of polio vaccine;
• Allergy history, history of asthma, including allergy history to vaccine or vaccine components, serious adverse reactions to the vaccine, such as urticaria, dyspnea, angioneurotic edema or stomachache, etc.;
• Congenital malformation or developmental disorder, genetic defect, serious malnutrition, etc.;
• Autoimmune disease or immunodeficiency/immunosuppression;
• Serious nervous system disorders (epilepsy, convulsion or tic) or mental disorders;
• Abnormal coagulation functions (such as coagulation factor deficiency, blood coagulation disease and blood platelet disorders) or obvious bruise or blood coagulation disorders diagnosed by the doctors;
• Receipt of immunosuppressant therapy, cytotoxic drug therapy and inhaled corticosteroid therapy (excluding the corticosteroid aerosol therapy for allergic rhinitis and surface corticosteroid therapy for acute non-complicated dermatitis);
• Receipt of blood products prior to this study;
• Receipt of other study drugs within 30 days prior to this study;
• Receipt of live attenuated vaccines within 14 days prior to this study;
• Receipt of subunit or inactivated vaccines within 7 days prior to this study;
• Acute diseases or acute exacerbation of chronic diseases within recent 7 days;
• Axillary temperature >37.0℃;
• Any other factors which are unsuitable for participation in the clinical trial as judged by the investigator.