A phase III, open, randomized, multicentre, multicountry study to compare the reactogenicity and evaluate the safety and immunogenicity of GSK Bio’s combined hepatitis A / hepatitis B vaccine (at least 720 EL.U of hepatitis A antigen and 20 µg of hepatitis B surface antigen per dose of 1 ml) administered according to a 0, 6 month schedule by intramuscular injection versus Twinrix™ Junior (at least 360 EL.U of hepatitis A antigen and 10 µg of hepatitis B surface antigen per dose of 0.5 ml) administered according to a 0, 1, 6 month schedule by intramuscular injection in healthy children between 1 to 11 years old.

INTERVENTION: Trade Name: Twinrix Adult Product Code: HAB Adult Pharmaceutical Form: Suspension for injection INN or Proposed INN: ‐ Current Sponsor code: HAV Other descriptive name: HEPATITIS A VIRUS (INACTIVATED) Concentration unit: ELISA unit/dose enzyme‐linked immunosorbent assay unit/dose Concentration type: equal Concentration number: 720‐ INN or Proposed INN: ‐ Current Sponsor code: HBsAg Other descriptive name: HEPATITIS B SURFACE ANTIGEN Concentration unit: µg microgram(s) Concentration type: equal Concentration number: 20‐ Trade Name: Twinrix Paediatric Product Code: HAB Ped Pharmaceutical Form: Suspension for injection INN or Proposed INN: ‐ Current Sponsor code: HBsAg Other descriptive name: HEPATITIS B SURFACE ANTIGEN Concentration unit: µg microgram(s) Concentration type: equal Concentration number: 10‐ INN or Proposed INN: ‐ Current Sponsor code: HAV Other descriptive name: HEPATITIS A VIRUS (INACTIVATED) Concentration unit: ELISA unit/dose enzyme‐linked immunosorbent assay unit/dose Concentration type: equal Concentration number: 360‐ CONDITION: Therapeutic area: Diseases [C] ‐ Virus Diseases [C02] Vaccination of healthy children from 1 to 11 years old against Hepatitis PRIMARY OUTCOME: Main Objective: For the primary study:; To demonstrate that the combined hepatitis A / hepatitis B (720/20) vaccine is not more reactogenic than Twinrix™ Junior.; ; For the long term follow up (LTFU):; To evaluate anti‐HAV and anti‐HBs antibody persistence at Year 2, Year 3, Year 4 and Year 5 after the first vaccine dose of the primary vaccination course (a two‐dose schedule of Twinrix Adult 720/20 vaccine or a three‐dose schedule of Twinrix Junior 360/10 vaccine).; To evaluate the immune memory in the subjects who became seronegative for anti‐HAV antibodies (i.e. anti‐HAV antibody concentrations < 15 mIU/ml) or had anti‐HBs antibody concentrations < 10 mIU/ml at the long‐term blood sampling time‐point (i.e. Year 2, 3, 4 or 5) and who received the challenge dose (administered 6 to 12 months after the Year 5 time‐point).; Primary end point(s): Overall number of subjects reporting with at least one grade 3 solicited symptom.; For the LTFU:; Anti‐HAV seropositivity rates and geometric mean concentrations (GMCs) (calculated on seropositive subjects).; Anti‐HBs seropositivity rates, proportion of the subjects with antibody concentrations >=10 mIU/ml and GMCs (calculated on seropositive subjects).; Secondary Objective: To assess the reactogenicity after each vaccine dose.; To assess the safety throughout the study.; To evaluate the immunogenicity elicited by the study vaccines, by measuring the anti‐Hepatitis A virus (HAV) and anti‐Hepatitis B surface antigen (HBs) antibody levels reached one month following the last vaccine dose (month 7).; Timepoint(s) of evaluation of this end point: For primary study: On the day of vaccination (Day 0) and during the 3 day follow‐up period after each vaccine dose (Day 0‐3).; For LTFU: At all the LTFU time‐points (at Years 2, 3, 4 and 5). SECONDARY OUTCOME: Secondary end point(s): Frequency and intensity of local solicited symptoms. ; Frequency, intensity and relationship of general solicited symptoms. ; Frequency, intensity and relationship of unsolicited symptoms. ; Frequency, intensity and relationship of serious adverse events (SAEs). ; ; For LTFU : ; Anti‐Hepatitis A virus (HAV) and anti‐Hepatitis B surface antigen (HBs) antibody titres. ; Seroconversion rate (SC) and geometric mean titres (GMTs) for anti‐HAV antibodies. ; SC rate, seroprotection (SP) and GMTs for anti‐HBs antibodies. ; Timepoint(s) of evaluation of this end point: For solicited local and general symptoms: On the day of vaccination (Day 0) and during the 3 day follow‐up period after each vaccine dose (Day0‐3). ; SAEs that are determined by the investigator to have a causal relationship to primary vaccination, any event related to a lack of vaccine efficacy (i. e. hepatitis A or hepatitis B infection), SAEs that are related to study participation (blood sampling). ; For unsolicited symptoms: Within 30 days after each vaccine dose and overall. ; For SAEs: During the study up to 30 days after the last vaccination. ; For anti‐HAV and anti‐HBs antibody titres at LTFU time point: At Month 0 and Month 7 for all subjects. ; For seroprotection, seroconversion and GMTs at LTFU time point: At Month 7 for all subjects. ; For SAEs at LTFU time points : At all the LTFU time‐points (at Years 2, 3, 4 and 5). INCLUSION CRITERIA: Fro the primary study: A male or female between, and including, 1 and 11 years of age at the time of the first vaccination. Written informed consent obtained from the parent or guardian of the subject and/or the subject. Free of obvious health problems as established by medical history and clinical examination before entering into the study. Not known to be seropositive for anti‐HAV antibodies, HBs antigen, anti‐HBc and anti‐HBs antibodies. Although very unlikely in this age group, female partici‐pants who may be at risk of becoming pregnant should take precautions to avoid pregnancy. For the LTFU: Subjects who had received at least one dose of the study vaccine in the primary study HAB‐120. Written informed consent was obtained from the parents or guardians of the subject before the blood‐sampling visit of each follow‐up visit. Are the trial subjects under 18? yes Number of subjects for this age range: 511 F.1