The purpose of this phrase III clinical trial is to evaluate the immunogenicity and safety of Sabin Inactivated Poliovirus Vaccine (Vero cell) in a '2+1'sequential schedule with bivalent oral poliovirus vaccine in 2-month-old infants

his study is a randomized, double-blind, active-controlled phrase III clinical trial. The purpose of this study is to evaluate the immunogenicity and safety of sIPV manufactured by Sinovac Biotech Co., Ltd in a '2+1' sequential schedule with bOPV in 2-month-old infants. 240 infants aged between 60-90 days will be randomly assigned into experimental group or control group in the ratio 1:1. The experimental group received sIPV-sIPV-bOPV vaccination schedule at one month doses interval (i.e., month 0, 1, 2), and the control group received wIPV-wIPV-bOPV vaccination schedule at one month doses interval (i.e., month 0, 1, 2). The control wIPV was manufactured by SANOFI PASTEUR S.A.

Inclusion Criteria:

• Healthy volunteer between 60-90 days old;
• Healthy volunteers who fulfill all the required conditions for receiving the investigational vaccine as established by medical history and clinical examination and determined by investigators;
• Proven legal identity;
• Participants or guardians of the participants should be capable of understanding the written consent form, and such form should be signed prior to enrolment;
• Complying with the requirement of the study protocol;

Exclusion Criteria:

• Prior vaccination with Poliovirus Vaccine;
• History of allergy to any vaccine, or any ingredient, excipients and Gentamycin Sulfate of the vaccine, or serious adverse reaction(s) to vaccination, such as urticaria, dyspnea, angioneurotic edema, abdominal pain, etc;
• Congenital malformation, developmental disorders, genetic defects, or severe malnutrition;
• Autoimmune disease or immunodeficiency/immunosuppressive;
• Severe/uncontrollable nervous system disease (epilepsy, seizures or convulsions) or mental illness;
• Diagnosed coagulation function abnormal (e.g., coagulation factor deficiency, coagulation disorder, or platelet abnormalities) , or obvious bruising or coagulation disorders;
• Any immunosuppressant, cytotoxic medicine, or inhaled corticosteroids (except corticosteroid spray for treatment of allergic rhinitis or corticosteroid treatment on surface for acute non-complicated dermatitis) prior to study entry;
• Blood product prior to study entry;
• Any other investigational medicine(s) within 30 days prior to study entry;
• Any live attenuated vaccine within 14 days prior to study entry;
• Any subunit vaccine or inactivated vaccine within 7 days prior to study entry;
• Acute disease or acute stage of chronic disease within 7 days prior to study entry;
• Axillary temperature > 37.0 °C;
• Any other factor that suggesting the volunteer is unsuitable for this study based on the opinions of investigators;