• Occurrence of SAEs [ Time Frame: From dose 1 up to Day 30 after dose 3 and from Dose 1 up to the day preceding the booster dose ]
  
• Occurrence of specific adverse events of new onset of chronic illness(es), rash, and conditions prompting emergency room visits [ Time Frame: From dose 1 up to Day 30 after dose 3 and from Dose 1 up to the day preceding the booster dose ]
  

• No secondary outcome measures for the primary vaccination
  

Pediarix/Infanrix Penta and Prevnar should be co-administered to all subjects in all study groups according to a 2, 4, and 6 month schedule concomitantly with study vaccines.

Inclusion Criteria:

• Subjects for whom the investigator believes that parents/guardians can and will comply with the requirements of the protocol.
• A male or female between, and including, 6 and 12 weeks of age at the time of the first vaccination.
• Written informed consent obtained from the parent or guardian of the subject.
• Healthy subjects as established by medical history and clinical examination before entering into the study.
• Born after 36 weeks gestation.
• Infants who have not received a previous dose of hepatitis B vaccine or those who have received only 1 dose of hepatitis B vaccine administered at least 30 days prior to enrolment.
• Infants may have received a birth dose of Bacillus Calmette-Guérin (BCG) vaccine.

Exclusion criteria:

Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine(s) within 30 days preceding the first dose of study vaccine, or planned use during the study period.

• Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs since birth.
• Planned administration/ administration of a vaccine not foreseen by the study protocol within 30 days of the first dose of study vaccine(s).
• Previous vaccination against Neisseria meningitidis, Haemophilus influenzae type b, diphtheria, tetanus, pertussis, and/or poliovirus; more than one previous dose of hepatitis B vaccine.
• In country(ies) where Prevnar will be provided by GSK Biologicals, previous vaccination with Prevnar.
• History of Neisseria meningitidis, Haemophilus influenzae type b, diphtheria, tetanus, pertussis, hepatitis B, and/or poliovirus disease.
• Any confirmed or suspected immunosuppressive or immunodeficient condition based on medical history and physical examination.
• History of allergic disease or reactions likely to be exacerbated by any component of the vaccines, including dry natural latex rubber.
• Major congenital defects or serious chronic illness.
• History of any neurologic disorders or seizures.
• Acute disease at time of enrollment.
• Administration of immunoglobulins and/or any blood products since birth or planned administration during the study period.
• Concurrent participation in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational product (pharmaceutical product or device).