Immunogenicity Study of Antibody Persistence and Booster Effect of PENTAXIM™ at 18 Months in Healthy Argentinean Infants

Inclusion Criteria: Toddler at 18 months of age (range: 510 days to 578 days of age inclusive) Participated in study A3L02 (NCT00831311) and has completed the three-dose primary series with either diphtheria, tetanus, pertussis (2-component acellular), recombinant Hepatitis B Hansenula and poliomyelitis vaccine adsorbed, and Haemophilus influenzae type b vaccine, conjugated to tetanus protein (DTaP-IPV-HB-PRP~T) or PENTAXIM™ and ENGERIX B® PEDIATRICO at 2, 4, and 6 months of age Written informed consent form signed by at least one parent or by a legal representative and an independent witness Able to attend all scheduled visits and to comply with all trial procedures. Exclusion Criteria: Participation in another clinical trial in the four weeks preceding the trial vaccination Planned participation in another clinical trial during the present trial period 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 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 six months Any vaccination in the four weeks preceding the trial Vaccination with a vaccine containing diphtheria, tetanus, pertussis, Haemophilus influenzae type b, polio, or hepatitis B antigen, since the end of the primary series History of documented diphtheria, tetanus, pertussis, Haemophilus influenzae type b, polio, or hepatitis B infection(s) (confirmed either clinically, serologically, or microbiologically) Thrombocytopenia or bleeding disorder contraindicating intramuscular vaccination History of seizures Fever (axillary temperature ≥37.4°C or equivalent rectal temperature ≥38.0°C) or acute illness on the day of inclusion Known contraindication to further vaccination with a pertussis vaccine such as: Encephalopathy; Inconsolable crying for >3 hours within 48 hours following vaccine injection Hypotonic hyporesponsive episode within 48 hours following vaccine injection Seizures with or without fever within three days following vaccine injection Axillary temperature >39.4°C or equivalent rectal temperature > 40.0°C within 48 hours following vaccine injection.