Sequential Inactivated Poliomyelitis Vaccine Followed by Oral Poliomyelitis Vaccine Versus Oral Poliomyelitis Vaccine

Immunogenicity and Safety of Different Sequential Schedules of Inactivated Poliomyelitis Vaccine (IMOVAX Polio®) Followed by Oral Poliomyelitis Vaccine in Healthy Infants in China Versus Oral Poliomyelitis Vaccine Alone.

The purpose of this study is to generate data to support the registration extension of IMOVAX Polio to be used in a sequential vaccination.

Primary objective:

• To demonstrate the non-inferiority of Inactivated Poliomyelitis Vaccine (IPV)-(Oral Poliomyelitis Vaccine) (OPV)-OPV (Sequential 1) and IPV-IPV-OPV (sequential 2) poliovirus vaccine administrations versus OPV-OPV-OPV (Reference) in terms of seroprotection rate 28 to 42 days after the third dose of the primary vaccination series.

Secondary objectives:

• To evaluate the safety profile of the investigational vaccines after each administration in each group.
• To describe the humoral immune response to poliovirus serotypes (types 1, 2 and 3) before the first dose and 28 to 42 days after the third primary series dose of vaccine in each group.
• To describe the persistence of antibodies against poliovirus serotypes (types 1, 2 and 3) after the third primary series dose administration, at 18 months of age in each group.

Study participants will be randomized to receive either 3 doses of a commercially available Oral Poliovirus Vaccine (OPV), or 1 dose of Sanofi Pasteur's injectable Inactivated Poliovirus Vaccine IMOVAX Polio (IPV) followed by 2 doses of OPV, or 2 doses of IPV followed by 1 dose of OPV.

These vaccines will be administered at 2, 3 and 4 months of age as primary vaccination for the prevention of poliomyelitis. Participants will be followed up through their 18th- to 19th-month birthday.

Inclusion Criteria:

• Aged ≥2 months and less than 3 months on the day of first study vaccine administration
• Born at full term of pregnancy (≥37 weeks) and with a birth weight ≥2.5 kg
• Informed consent form has been signed and dated by the parent or other legally acceptable representative
• Subject and parent/legally acceptable representative are able to attend all scheduled visits and to comply with all trial procedures.

Exclusion Criteria:

• Participation in the 4 weeks preceding the first trial vaccination or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure
• Receipt or planned receipt of any vaccine in the 4 weeks preceding or following any trial vaccination (except Diphtheria, Tetanus, acellular Pertussis vaccine [DTaP], Haemophilus Influenzae Type b [Hib] vaccine, bacille Calmette-Guerin vaccine [BCG] and Hepatitis B given at least 7 days before and after study vaccination)Previous vaccination against poliomyelitis with either the trial vaccine or another vaccine
• Receipt of immune globulins, blood or blood-derived products since birth
• Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy since birth; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks since birth)
• Congenital or acquired immunodeficiency in close contacts to the subjects
• History of poliomyelitis infection (confirmed either clinically, serologically or microbiologically)
• At high risk for human immunodeficiency virus (HIV) infection during the trial
• Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccines used in the trial or to a vaccine containing any of the same substances
• Laboratory-confirmed or otherwise known thrombocytopenia, contraindicating intramuscular vaccination
• Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular vaccination
• Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily
• Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion
• Moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (axillary temperature ≥37.1°C). A prospective subject should not be included in the study until the condition has resolved or the febrile event has subsided
• Identified as a natural or adopted child of the Investigator or employee with direct involvement in the proposed study
• Any other contraindication as listed in the study vaccines' leaflets.