Immunogenicity and Safety of a Fractional Booster Dose of IPV Intradermally Versus Full Dose Intramuscularly

Inclusion Criteria: * Aged 15 to 18 months on the day of inclusion * Informed consent form signed by the parent(s) or other legally acceptable representative * Subjects and parent/guardian able to attend all scheduled visits and comply with all trial procedures * Child having completed all visits of the IPV25 study (NCT00604058), including the three-dose primary vaccination series with the study vaccine (IMOVAX Polio), using the route of administration as designated by randomization. Exclusion Criteria: * Participation in another clinical trial investigating a vaccine, drug, medical device, or a medical procedure in the 4 weeks preceding the trial vaccination * Planned participation in another clinical trial during the present trial period * Known or suspected congenital or acquired immunodeficiency, immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months, or long-term systemic corticosteroids therapy * Known systemic hypersensitivity to any of the vaccine components or history of a life-threatening reaction to the trial vaccine or to a vaccine containing any of the same substances * Chronic illness at a stage that could interfere with trial conduct or completion, in the opinion of the investigator * Receipt of blood or blood-derived products since birth that might interfere with the assessment of immune response * Receipt of any vaccine in the 4 weeks preceding the trial vaccination * Planned receipt of any vaccine during the present trial period * Known personal or maternal Human Immunodeficiency Virus (HIV), Hepatitis B antigen or Hepatitis C seropositivity * History of seizures * History of poliomyelitis infection (confirmed either clinically, serologically or microbiologically) * Previous fourth dose vaccination against the poliomyelitis disease with either the trial vaccine or another vaccine * Thrombocytopenia, bleeding disorder or anticoagulants in the 3 weeks preceding inclusion contraindicating IM injection * Febrile illness (temperature ≥38.0 °C) or moderate or severe acute illness/infection on the day of vaccination, according to investigator judgment.