Long-term Immune Persistence of GSK Biologicals' Combined Hepatitis A & B Vaccine Injected According to a 0,1,6 Mth Schedule in Healthy Adults

Primary outcomes

1. Number of Subjects With Anti-hepatitis A (Anti-HAV) Antibody Concentrations Equal to or Above Cut-off Value

   Time frame: Years 11, 12, 13, 14 and 15

   Cut-off value was defined as 15 milli-international units per milliliter (mIU/mL). This was considered as seropositivity.

2. Number of Subjects With Anti-hepatitis B Surface Antigen (Anti-HBs) Antibody Concentrations Equal to or Above Cut-off Values

   Time frame: Years 11, 12, 13, 14 and 15

   Cut-off values were defined 3.3 mIU/mL for the in-house anti-HBs assay and 6.2 mIU/mL for the ChemiLuminescence ImmunoAssay, which was also considered as seropositivity, and 10 mIU/mL.

3. Anti-HAV and Anti-HBs Antibody Concentrations

   Time frame: Years 11, 12, 13, 14 and 15

   Concentrations are expressed as geometric mean concentrations (GMCs) in mIU/mL.

   The laboratory assay was changed from Year 13 to Year 14 to in-house ELISA and at Year 15 to CLIA for anti-HBs GMCs.Thus for the sake of bridging, blood samples corresponding to Year 14 previously tested with ELISA were re-tested with CLIA (Year 14*).

4. Anti-HBs Antibody Concentrations

   Time frame: at Year 11, pre-additional vaccine, after additional dose of Engerix

   Subjects who lost seroprotective concentrations for anti-HBs (< 10 mIU/mL) at any of the LT follow-up timepoints received an additional dose of Engerix after year 15.

   Two subjects were eligible for this after Year 11.

   3.29 in the table means a concentration of < 3.3 mIU/mL.

   As the concentration was calculated per subject no mean concentration was calculated and also no measure of dispersion.

5. Number of Subjects, Receiving an Additional Vaccination of Engerix, With an Anamnestic Response

   Time frame: 30 days post additional dose of Engerix

   Anamnestic response was assessed in subjects receiving an additional vaccine dose of Engerix. Two subjects were found eligible at Year 11 for this additional vaccine dose.

   Anamnestic response was defined as:

   • post-additional vaccination anti-HBs concentration >= 10 mIU/mL in subject seronegative before additional dose.
   • 4-fold increase post-additional dose compared to pre-additional vaccine time point.

6. Number of Subjects With Solicited Local and General Symptoms Assessed

   Time frame: During the 4-day follow-up period after additional vaccination with Engerix

   Solicited local symptoms were pain, redness and swelling. Solicited general symptoms were fatigue, fever, gastrointestinal, headache.

7. Number of Subjects With Unsolicited Symptoms

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

   Unsolicited 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.

8. Number of Subjects With Serious Adverse Events (SAEs)

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

   SAEs assessed include medical occurrences that result in death, are 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

9. Number of Subjects With Serious Adverse Events (SAEs) Determined by the Investigator to Have a Causal Relationship to Primary Vaccination or Due to Lack of Vaccine Efficacy

   Time frame: up to Year 11, 12, 13, 14, 15

   SAEs assessed include medical occurrences that result in death, are 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.