Long-Term Immune Persistence of GSK Biologicals' Combined Hepatitis A & B Vaccine Injected According to a 0,6 Month Schedule

• Anti-hepatitis A Virus (Anti-HAV) Antibody Concentration [ Time Frame: Years 6, 7, 8, 9, and 10. ] [ Designated as safety issue: No ]
  
• Anti-hepatitis B Surface Antigen (Anti-HBs) Antibody Concentration [ Time Frame: At Year 6, 7, 8, 9 and 10 ] [ Designated as safety issue: No ]
  
• Anti-hepatitis B Surface Antigen (Anti-HBs) Antibody Concentration [ Time Frame: Before and 1 month after the additional dose administration ] [ Designated as safety issue: No ]
  
• Number of Subjects With Immune Response to the Additional Dose of Engerix™-B [ Time Frame: One month after the additional dose administration ] [ Designated as safety issue: No ]

  Immune response was defined as:

  • anti-hepatitis B surface antigen (anti-HBs) antibody concentration equal or above to 10 milli-international units per milliliter (mIU/mL) at 1 month post-challenge dose in subjects seronegative at the pre-challenge time-points
  • at least a 4-fold increase in anti-HBs antibody concentrations at 1 month post-challenge dose in subjects seropositive at the pre-challenge time-points.
  
  
• Number of Subjects Reporting Serious Adverse Events (SAEs) Assessed by the Investigator as Causally Related to Primary Vaccination, Study Procedures or Lack of Vaccine Efficacy [ Time Frame: At Year 6, 7, 8, 9 and 10 ] [ Designated as safety issue: No ]
  Serious adverse events (SAEs) assessed include medical occurrences that result in death, is life threatening, require hospitalization or prolongation of hospitalization, result in disability/incapacity or are a congenital anomaly/birth defect in the offspring of a study subject.
  
  
• Number of Subjects Reporting Solicited Local and General Symptoms [ Time Frame: During the 4-day follow-up period after additional dose ] [ Designated as safety issue: No ]
  Solicited local symptoms assessed include pain, redness and swelling. Solicited general symptoms assessed include fatigue, fever, gatrointestinal symptoms and headache.
  
  
• Number of Subjects Reporting Unsolicited Adverse Events [ Time Frame: During the 30-day follow-up period after additional dose ] [ Designated as safety issue: No ]
  Unsolicited adverse event (AE) covers any AE reported in addition to those solicited during the clinical study and any solicited symptom with onset outside the specified period of follow-up for solicited symptoms.
  
  
• Number of Subjects Reporting Serious Adverse Events (SAEs) [ Time Frame: During the 30-day follow-up period after additional dose ] [ Designated as safety issue: No ]
  Serious adverse events (SAEs) assessed include medical occurrences that result in death, is life threatening, require hospitalization or prolongation of hospitalization, result in disability/incapacity or are a congenital anomaly/birth defect in the offspring of a study subject.
  
  

To evaluate the long-term antibody persistence, volunteers will be bled at Years 6, 7, 8, 9 and 10 after the first vaccine dose of the primary vaccination course to determine their anti-HAV and anti-HBs antibody concentrations.

If a subject has become seronegative for anti-HAV antibodies or lost anti-HBs seroprotection concentrations at the long-term blood sampling time point (i.e. Years 6, 7, 8, 9 or 10), he/ she will be offered an additional vaccine dose.