Long-Term Immune Persistence of GSK Biologicals' Combined Hepatitis A & B Vaccine Injected According to a 0,1,6 Month Schedule

Primary outcomes

1. Anti-hepatitis A Virus (Anti-HAV) Antibody Concentration

   Time frame: At Years 11, 12, 13, 14, and 15 after the first vaccine dose of the 3-dose primary vaccination

   Concentrations given as geometric mean concentration (GMC) expressed as milli-international unit per millilitre (mIU/mL).

2. Number of Subjects Reporting Any and Grade 3 Solicited Local Symptoms.

   Time frame: During the 4-day (Day 0-3) follow-up period after additional HBV vaccination

   Solicited local symptoms assessed include pain, redness and swelling. Any was defined as occurrence of the specified solicited local symptom regardless of its intensity. Grade 3 pain was defined as pain that prevented normal everyday activities. Grade 3 swelling was greater than 100 millimeters (mm) i.e. >100mm.

3. Number of Subjects Seropositive for Anti-HAV Antibodies

   Time frame: At Years 11, 12, 13, 14, and 15 after the first vaccine dose of the 3-dose primary vaccination

   A seropositive subject was defined as a vaccinated subject who had a anti-HAV antibody titres ≥ 33 mIU/ml.

4. Anti-hepatitis B Surface Antigen (Anti-HBs) Antibody Concentration

   Time frame: At Years 11, 12, 13, 14, and 15 after the first vaccine dose of the 3-dose primary vaccination

   Concentrations given as GMC expressed as mIU/mL. NOTE: There was a change of assay kit at Year 15 time-point, thus for the sake of bridging, blood samples corresponding to Year 14 were re-tested with ChemiLuminescence ImmunoAssay (CLIA). From Year 11 to Year 14, anti-HBs antibody concentrations were tested with ELISA with cut-off of 3.3 mIU/mL while, Year 14* onwards, anti-HBs antibody concentrations were tested with the CLIA with cut-off of 6.2 mIU/mL.

5. Number of Subjects Seropositive for Anti-HB Antibodies

   Time frame: At Years 11, 12, 13, 14, and 15 after the first vaccine dose of the 3-dose primary vaccination

   A seropositive subject was defined as a vaccinated subject who had anti-HB antibody titres ≥ 1 mIU/mL.

   NOTE: There was a change of assay kit at Year 15 time-point, thus for the sake of bridging, blood samples corresponding to Year 14 were re-tested with ChemiLuminescence ImmunoAssay (CLIA)

6. Number of Subjects Seroprotected for Anti-HBs Antibodies.

   Time frame: At Years 11, 12, 13, 14, and 15 after the first vaccine dose of the 3-dose primary vaccination

   A seroprotected subject was defined as a subjects with the anti-HBs titres ≥ 10 mIU/mL.

   NOTE: There was a change of assay kit at Year 15 time-point, thus for the sake of bridging, blood samples corresponding to Year 14 were re-tested with ChemiLuminescence ImmunoAssay (CLIA)

7. Number of Subjects Reporting Serious Adverse Events (SAE)

   Time frame: During the follow-up period after additional vaccination (minimum 30 days)

   A SAE was defined as any untoward medical occurrence that: resulted in death, was life threatening, required hospitalization or prolongation of hospitalization, resulted in disability/incapacity or was a congenital anomaly/birth defect in the offspring of a study subject. Any was defined as occurrence of any symptom regardless of intensity grade or relation to vaccination and related was an event assessed by the investigator as causally related to the study vaccination.

8. Anti-Hepatitis B Surface Antigen (Anti-HBs) Antibody Concentration

   Time frame: Before the additional dose and 1 month after the additional dose

   Concentrations given as GMC expressed as mIU/mL. If a subject became seronegative (< 10 mIU/mL) at any of the long-term blood sampling timepoint, he/she was offered an additional vaccine dose.

9. Number of Subjects Reporting Any Solicited General Symptoms.

   Time frame: During the 4-day (Day 0-3) follow-up period after additional HBV vaccination

   Solicited general symptoms assessed included fatigue, headache, malaise, nausea, vomiting and fever. Any was defined as any solicited general symptom reported irrespective of intensity and relationship to vaccination.

10. Number of Subjects Reporting Unsolicited Adverse Events (AE)

    Time frame: During the 30-day follow-up period after additional vaccination

    An AE is any untoward medical occurrence in a clinical investigation subject, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.

11. Number of Subjects Reporting Serious Adverse Events (SAEs)

    Time frame: At Years 11, 12, 13, 14, and 15 after the first vaccine dose of the 3-dose primary vaccination

    A SAE was defined as any untoward medical occurrence that: resulted in death, was life threatening, required hospitalization or prolongation of hospitalization, resulted in disability/incapacity or was a congenital anomaly/birth defect in the offspring of a study subject. Any was defined as occurrence of any symptom regardless of intensity grade or relation to vaccination and related was an event assessed by the investigator as causally related to the study vaccination.