The purpose of this study is to evaluate safety and immunogenicity of Pediacel® in infants and toddlers when given at 2,3,4 and 12-18 months of age.

Primary Objectives:

• To compare the post-dose 3 immunogenicity of Pediacel® to Infanrix®-IPV+Hib when both are co-administered with Prevenar®.
• To describe the post-dose 3 pertussis antibody responses.

Secondary Objectives:

• To compare the post-dose 4 immunogenicity of Pediacel® to Infanrix®-IPV+Hib when both are co-administered with Prevenar®.
• To describe the safety after each vaccination following co-administration with Prevenar®.

Inclusion Criteria:

• Infants 55 to 75 days old, inclusive on the day of first vaccination
• Born at full term of pregnancy (> 37 weeks)
• Informed consent form signed by the parent(s) or the legal guardian
• Parents or the legal guardian able to read and write in the local language
• Parent(s) or the legal guardian able to attend all scheduled visits and to comply with the study procedures.

Exclusion Criteria:

• Presence of fever (defined as rectal body temperature ≥ 38.0°C) reported within the last 72 hours
• Moderate or severe acute illness with or without fever
• Participation in another clinical trial in the 30 days preceding first study vaccination
• Planned participation in another clinical trial during the present study period
• Received diphtheria, tetanus, pertussis, poliomyelitis, Haemophilus influenzae type b or a pneumococcal vaccine separately or in combination prior to study vaccination
• Received any vaccination in the 30 days preceding the first study vaccination and/or is planning any vaccination within 6 weeks following any of the study vaccinations
• Congenital or acquired humoral/cellular immunodeficiency or immunosuppressive therapy such as long-term systemic corticosteroids therapy (≥ 2 mg/kg/day prednisone equivalent for ≥ 14 days) in the previous 30 days
• Systemic or local hypersensitivity to any of the study vaccine components (including neomycin, streptomycin, polymyxin B and formaldehyde)
• History of life-threatening reaction(s) (such as encephalopathy, Hypotonic-Hyporesponsive Episode, rectal body temperature ≥ 40.0°C, convulsions with or without fever) to any vaccine containing the same components as the study vaccines
• Blood or blood-derived products (immunoglobulins) received since birth
• Known Human immunodeficiency virus (HIV) seropositivity
• Known thrombocytopenia or other bleeding disorder contraindicating intramuscular vaccination
• History of encephalopathy, seizures or progressive, evolving or unstable neurological condition
• Clinically significant findings on review of systems that might interfere with study vaccination or which, in the opinion of the Investigator, would interfere with the evaluation of the study vaccine/objectives or pose a health risk to the subject.