Immunogenicity and Safety of Havrix™ Co-Administered With a Diphtheria, Tetanus and Pertussis and a Haemophilus b Vaccine in Children Aged 15 Months

Inclusion Criteria: * Subjects whose parents/guardians are believed by the investigator to be willing to comply with the requirements of the protocol * A male or female child 12 or 13 months of age at the time of entry into the Enrolment Phase, * Subjects must have previously received three doses each of DTaP and Hib vaccines during the first year of life. The three doses of DTaP vaccine must have been administered as either Infanrix™ or Pediarix™ and the three doses of Hib vaccine must have been administered as ActHIB™, HibTITER™, OmniHIB™. * Subjects who, at 15 months of age, will have had at least six months elapse since their third dose of Infanrix™ or Pediarix™, * Written informed consent obtained from the parents or guardian of the subject, * Free of obvious health problems as established by medical history and history-directed physical examination before entering into the study, and * Parents/guardian of the subject must have a telephone or be able to be contacted by telephone. Exclusion Criteria: * Use of any investigational or non-registered drug or vaccine other than the study vaccine(s) within 31 days preceding the first dose of study vaccine, or planned use during the study period, * Chronic administration (defined as more than 14 days) of immuno-suppressant or other immune-modifying drugs within six months prior to vaccination or planned administration at any time during the study period. * Planned administration or administration of any vaccine not foreseen by the study protocol during the period 42 days before and 31 days after each dose of study vaccine(s). * Previous vaccination against DTaP using a commercially-available brand other than Infanrix™ or Pediarix™ or against Hib using a commercially-available brand other than ActHIB™, HibTITER™ or OmniHIB™. * Previous vaccination with more than three doses of DTaP-containing vaccines or more than three doses of Hib-containing vaccines. * Previous vaccination against hepatitis A, * History or known exposure to hepatitis A, * History of diphtheria, tetanus, pertussis and/or Haemophilus influenza type b, * Known exposure to diphtheria, tetanus, pertussis and/or Haemophilus influenza type b within 31 days prior to the start of the study, * History of non-response to any vaccine in the current routine immunization schedule, * Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection, * A family history of congenital, hereditary or infectious immunodeficiency or parental risk factors for HIV infection, * History of allergic disease/reactions or hypersensitivity likely to be exacerbated by any component of Havrix™, Infanrix™ or ActHIB™ including 2-phenoxyethanol, neomycin and gelatin, * History of hypersensitivity/allergic reaction to latex * Major congenital defects or serious chronic illness, * History of any neurologic disorder * Acute disease at the time of vaccination. * Administration of immunoglobulins and/or any blood products within three months prior to the first dose of study vaccine or planned administration at any time during the entire study period, i.e., the Enrolment Phase, the Active Phase and the Extended Safety Follow-up Phase