Immunogenicity and Safety of Liquid Bivalent Oral Poliomyelitis Vaccine

The purpose of this study will be to evaluate whether a bivalent oral polio vaccine (bOPV) manufactured by Beijing Bio-Institute Biological Products Co., Ltd (BBIBP) has a similar immunogenicity profile to a WHO prequalified bOPV.

BBIBP has been one of the two suppliers of trivalent oral polio vaccine (tOPV) in China since 1985, with control of polio in China evidence of the effectiveness of its vaccine. The company plans to introduce a liquid formulation of bOPV (types 1 and 3) to meet increasing global demand with the phasing-out of tOPV. The proposed study is intended to provide data sufficient to obtain World Heath Organization (WHO) prequalification for the BBIBP bOPV, thus making the vaccine available to help meet global demand.

Infants were enrolled and randomized prior to the birth dose of bOPV. The first dose of study vaccine was administered during the first two weeks of life and then co-administered with the primary Expanded Programme on Immunization (EPI) series vaccines in Kenya at 6, 10 and 14 weeks of age. The Kenya EPI schedule includes the following additional vaccines:

* Bacille Calmette-Guérin Vaccine (BCG) at birth
* Diphtheria and Tetanus Toxoid with Whole Cell Pertussis, Haemophilus influenzae Type V vaccine (Hib), and Hepatitis B Vaccine (DTwPHibHep) at 6, 10, 14 weeks;
* Pneumococcal Conjugate vaccine (PCV) at 6, 10, 14 weeks
* Rotavirus vaccine (Rotarix) at 6, 10 weeks

Eligibility Criteria:
Inclusion Criteria:

* Healthy, full-term infants, as established by medical history and clinical examination before entering into the study.
* Parents willing to provide written informed consent.
* Age: infants less than 2 weeks of age at the time of enrollment (from the 1st through the 14th day of life, inclusive)

Exclusion Criteria:

* Birth weight (as documented at first medical contact) less than 2.5 kg
* Presence of diarrhea or vomiting in the previous 24 hours or on the day of enrollment (temporary exclusion)
* Presence of fever (\> 37.5°C) on the day of enrollment (temporary exclusion)
* Acute disease at the time of enrollment (temporary exclusion)
* Significant malnutrition as per Investigator's judgment
* Concurrent participation in another clinical study at any time during the study period in which the infant will be exposed to an investigational or a non-investigational product
* Presence of any significant systemic disorder (cardiovascular, pulmonary, hepatic, renal, gastrointestinal, hematological, endocrine, immunological, dermatological, neurological, cancer or autoimmune disease) as determined by medical history and/or physical examination which would compromise the child's health or is likely to result in non-conformance to the protocol
* Known or suspected impairment of immunological function (including human immunodeficiency virus \[HIV\] exposure) based on medical history and physical examination
* Previous receipt of polio virus vaccine
* Household contact with a known immunosuppressed individual
* Unwillingness or inability of parents for active follow-up by the study staff
* History of any neurological disorders or seizures
* Any medical condition that, in the judgment of the investigator, would interfere with or serve as a contraindication to protocol adherence or a participant's ability to give informed consent
* Maternal HIV infection