Study of Immunogenicity and Safety of a Booster Dose of DTaP-IPV-HB-PRP~T Combined Vaccine in Healthy Turkish Infants

Inclusion Criteria: * Toddler previously included in Study A3L10 who completed the three-dose primary series vaccination of either DTaP-IPV-HB-PRP\~T or PENTAXIM™ and ENGERIX B® at 2, 3 and 4 months of age. * Toddler of 15 to 18 months of age (range: 456 to 578 days of age inclusive). * Informed Consent Form signed by the parent(s) or other legal representative(s) and an institution official other than an Investigator. * Able to attend all scheduled visits and to comply with all trial procedures. Exclusion Criteria: * Participation in another clinical trial in the 4 weeks preceding the booster vaccination. * Planned participation in another clinical trial during the present trial period. * Congenital or acquired immunodeficiency, immunosuppressive therapy such as long-term systemic corticosteroid therapy. * Systemic hypersensitivity to any of the vaccine components or history of a life-threatening reaction to a vaccine containing the same substances. * Chronic illness at a stage that could interfere with trial conduct or completion. * Blood or blood-derived products received in the last 3 months. * Any vaccination in the 4 weeks preceding the booster vaccination. * Any vaccination planned until second Visit. * History of documented pertussis, tetanus, diphtheria, polio, Haemophilus influenzae type b or hepatitis B infection(s) (confirmed either clinically, serologically or microbiologically). * Previous booster vaccination against pertussis, tetanus, diphtheria, polio or Haemophilus influenzae type b, and hepatitis B infection(s). * Coagulopathy, thrombocytopenia or a bleeding disorder contraindicating intramuscular vaccination. * Any vaccine-related serious adverse event that occurred following the three-dose primary series administration of the investigational vaccine or of the reference vaccine in Study A3L10 (NCT00315055). * Febrile (temperature ≥ 38.0°C) or acute illness on the day of inclusion. * Known contraindication to further vaccination with a pertussis vaccine, i.e.: Encephalopathy; temperature \> 40.0°C within 48 hours following a vaccine injection, not due to another identifiable cause during the primary series; Inconsolable crying that occurred for \> 3 hours within 48 hours following vaccine injection during the primary series; Hypotonic hyporesponsive episode within 48 hours following vaccine injection during the primary series; Seizures with or without fever within 3 days following vaccine injection.