Assess if Immune Response of GSK Biologicals' Tritanrix™-HepB/Hib-MenAC Given Without or With Hepatitis B Vaccine at Birth is at Least as Good as Tritanrix™-HepB/Hiberix™ Without Hepatitis B Vaccine at Birth, When Given to Healthy Infants

Study to Show Non-inferiority of Tritanrix™-HepB/Hib-MenAC (+/- Hepatitis B Vaccine at Birth) Versus Tritanrix™-HepB/Hiberix™ Without Hepatitis B Vacc. at Birth for Antibody Response to All Vaccine Antigens Given in Healthy Infants

The purpose of this study is to compare the immune response, safety and reactogenicity of Tritanrix™-HepB/Hib-MenAC vaccine given either with or without a birth dose of hepatitis B vaccine to Tritanrix™-HepB/Hiberix™ when given to healthy infants (born to mothers who do not carry hepatitis B virus) at 6, 10 & 14 weeks of age. This study will also include a small group of infants born to mothers who do carry hepatitis B virus; these infants will receive a birth dose of hepatitis B vaccine and will be vaccinated with Tritanrix™ HepB/Hib-MenAC at 6, 10 & 14 weeks age.

Randomized study with three groups (subjects born to mothers who do not carry hepatitis B virus) to receive one of the following vaccination regimens: - GSK Biologicals' Tritanrix™-HepB/Hib-MenAC and hepatitis B vaccine at birth

- GSK Biologicals' Tritanrix™-HepB/Hib-MenAC and no hepatitis B vaccine at birth - GSK Biologicals' Tritanrix™-HepB/Hiberix™ There will also be a fourth group (subjects born to mothers who do carry hepatitis B virus) to receive: - GSK Biologicals' Tritanrix™-HepB/Hib-MenAC and hepatitis B vaccine at birth

Inclusion criteria:

• Healthy infants aged 3 days or less, written informed consent obtained from the parents, born after a gestation period of 36 to 42 weeks.
• Result of the maternal blood sample (presence/not of hepatitis B virus) is available.

Exclusion criteria:

• Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination.
• A family history of congenital or hereditary immunodeficiency.
• Major congenital defects or serious chronic illness.
• History of any neurologic disorders or seizures.
• Administration of immunoglobulins and/or any blood products since birth or planned administration during the study period (except for immunoglobulins given at birth to infants born to HBsAg seropositive mothers).
• Acute disease at the time of enrolment.
• Known exposure to diphtheria, tetanus, pertussis, hepatitis B, Haemophilus influenzae type b and/or meningococcal disease.
• Hepatitis B vaccine given at birth outside the study.