Immunogenicity Study of Antibody Persistence and Booster Effect of DTaP-HB PRP~T Combined Vaccine in Filipino Infants

DTaP-HB-PRP\~T combined vaccine is being developed in order to comply with expanding programs for immunization in infancy, while offering the benefit of a reduced number of injections, and potentially of an increased acceptance.

Primary Objectives:

* To describe the antibody persistence at 12 to 18 months following a three-dose primary series vaccination of either DTaP-HB-PRP\~T or Tritanrix-Hep B/Hib™ given at 6, 10 and 14 weeks of age, and one dose of Hepatitis B (Hep B) vaccine given at birth.
* To describe the effect of a booster dose of DTaP-HB-PRP\~T on immunogenicity at 12 to 18 months following a three-dose primary series vaccination of either DTaP-HB-PRP\~T or Tritanrix HepB/Hib™ given at 6, 10 and 14 weeks of age, and one dose of Hep B vaccine given at birth.

Secondary Objective:

* To describe the safety profile of the booster dose of the DTaP-HB-PRP\~T vaccine when administered concomitantly with Oral Polio Vaccine (OPV).

This study will assess the immunogenicity and reactogenicity of the investigational DTaP-HB-PRP\~T combined vaccine when given as a booster dose, concomitantly with OPV, in Filipino children previously primed at 6, 10, and 14 weeks with the investigational DTaP-HB-PRP\~T combined vaccine or Tritanrix-Hep B/Hib™ vaccine and having received a first dose of Hep B vaccine (Recomvax B™) at birth in a previous study, AL201 (NCT00348881).

Eligibility Criteria:
Inclusion Criteria:

* Toddler aged 12 to 18 months of age on the day of inclusion (range: 365 days to 578 days of age inclusive)
* Participated in the AL201 study and completed the three-dose primary series with either DTaP-HB-PRP\~T or Tritanrix-HepB/Hib™, and OPV, at 6, 10 and 14 weeks of age, and received hepatitis B vaccine at birth
* Informed consent form signed by one parent or legal representative if appropriate (independent witness mandatory if parent is illiterate)
* 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 trial vaccination
* Planned participation in another clinical trial during the present trial period
* Congenital or acquired immunodeficiency, immunosuppressive therapy such as long-term (for more than 2 weeks) systemic corticosteroid therapy within the preceding 3 months
* Known 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 trial vaccination
* Vaccination planned in the 4 weeks following the trial vaccination
* Febrile (temperature ≥ 38.0°C) or acute illness on the day of inclusion
* History of documented diphtheria, tetanus, pertussis, Haemophilus influenzae type b, hepatitis B or poliomyelitis infection(s) (confirmed either clinically, serologically, or microbiologically)
* Vaccination with a vaccine containing diphtheria, tetanus, pertussis, Haemophilus influenzae type b, hepatitis B or poliovirus 3 types antigen, since the end of the primary series
* Thrombocytopenia or a bleeding disorder contraindicating IM vaccination
* Serious adverse event related to any vaccination in the AL201 study.