The purpose of this study is to evaluate the safety of sIPVs of different dosages in adults, children and infants in a phase I open-label study, and then assess its immunogenicity and safety in healthy infants between 60 and 90 days old in a phase II blind, randomized, and controlled study.

This study is a combination of phases I and II. Phase I study is open-label, and only collect safety information of the investigational sIPVs in adults, children and infants. Phase II study is double-blind, randomized, controlled study of the immunogenicity and safety of the investigational vaccines and two other commercialized inactivated poliovirus vaccines in healthy infants.

Inclusion Criteria:

• Healthy volunteer between 60-90 days old, 6-12 years old, or 18-49 years 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 (≥ 18 years old), or guardians of the participants (< 18 years old) 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;
• Axillary temperature ≤ 37.0 °C;

Exclusion Criteria:

• Breast feeding, pregnant, or expected to conceive in the next 60 days;

• History of allergy to any vaccine, or any ingredient 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;

• serious chronic diseases, serious cardiovascular disease, hypertension or diabetes that cannot be stabilized by medication, liver or kidney disease, malignancy, etc;

• severe nervous system disease (epilepsy, seizures or convulsions) or mental illness;

• History of thyroidectomy, asplenia, functional asplenia, or any condition resulting in the absence or removal the spleen;

• Bleeding disorder diagnosed by a doctor (e.g., coagulation factor deficiency, coagulation disorder, or platelet disorder) , or significant bruising or coagulopathy;

• Long term history of alcoholism or drug abuse;

• Receipt of any of the following products:

  1. Any subunit or inactivated vaccine within the past 7 day;
  2. Any live attenuated vaccine within the past 14 days;
  3. Any other investigational medicine(s) within the past 30 days;
  4. Any blood product within the past 3 months;
  5. Any immunosuppressant, cytotoxic medications, or inhaled corticosteroids (except corticosteroid spray for treatment of allergic rhinitis or corticosteroid treatment on surface for acute non-complicated dermatitis) within the past 6 month prior to study entry;

• Acute illness or acute exacerbation of chronic disease within the past 7 days;

• Axillary temperature > 37.0 °C;

• Infant participants with prior vaccination of poliovirus;

• Any other factor that, in the judgment of the investigator, suggesting the volunteer is unsuitable for this study;