Antibody Persistence at Age 3.5 and 4.5 Years After Primary and Booster DTaP-IPV-Hep B-PRP~T or Infanrix Hexa Vaccination

Inclusion Criteria: * Aged 3 years and a half (42 months ± 60 days) on the day of the first study visit * Informed consent form has been signed and dated by the parent(s) or other legally acceptable representative (and by independent witness/es if required by local regulations) * Subject and parent/legally acceptable representative are able to attend all scheduled visits and to comply with all trial procedures * Receipt of primary vaccination with 3 doses of investigational vaccines during the primary series trial A3L24 (either DTaP-IPV-Hep B-PRP-T or Infanrix hexa, concomitantly administered with Prevenar \[PCV7\] and Rotarix) and a booster dose during the trial A3L27 (either DTaP-IPV-Hep B-PRP-T or Infanrix hexa, concomitantly administered with Prevenar \[PCV7\]). Exclusion Criteria: * Participation at the time of study enrollment (or in the 4 weeks preceding the first trial visit) or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure * Incomplete primary and booster immunization at trial A3L24 and A3L27 * Receipt of any vaccine in the 4 weeks preceding the first trial visit or planned receipt of any vaccine in the 4 weeks preceding the second trial visit * Previous vaccination against diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B, or Haemophilus influenzae type b infections with other vaccine(s) after completion of A3L27 study * Receipt of immune globulins, blood or blood-derived products in the past 3 months * Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 3 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months) * History of diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B, or Haemophilus influenzae type b infection(s), confirmed either clinically, serologically, or microbiologically after completion of trial A3L27 * Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating blood drawn * Acute or chronic illness that, in the opinion of the Investigator, is at a stage where it might interfere with trial conduct or completion.