Development of Read-outs in Healthy, Hepatitis B Virus Naive Adults Vaccinated With the Hepatitis B Surface Antigen (HBsAg) in Combination With a GlaxoSmithKline (GSK) Biologicals' Adjuvant System

This study aims to develop innovative immunological read-outs and new technologies in order to further characterise the early immune response and its kinetics as well as the adaptive immune responses to adjuvanted vaccines.

This study will also evaluate the reactogenicity in healthy, hepatitis B virus naive adults vaccinated with the hepatitis B surface antigen in combination with a GSK Biologicals' Adjuvant System.

This study will be conducted in 2 steps with 2 study groups in each step. The entire study period for Step 1 is from Day -30 to Day 210 (240 days) The entire study period for Step 2 is from Day 0 to Day 180 for Group C and from Day 0 to Day 330 for Group D.

Subjects will be blinded up to Day 60 in Step 1 and will be unblinded at the end of their Day 60 visit. Step 2 will be conducted in an open-label manner.

Eligibility Criteria:
Inclusion Criteria:

* Subjects who, in the opinion of the investigator, can and will comply with the requirements of the protocol
* A male or female between, and including, 18 and 45 years of age at the time of first study product administration
* Written informed consent obtained from the subject
* Healthy subjects, in the opinion of the investigator, as established by medical history, clinical examination, and clinical laboratory assessment with no active disease that could interfere with the study endpoints, before entering into the study
* Body Mass Index (BMI) between 18.5 and 30 kg/m2
* Female subjects of non-childbearing potential may be enrolled in the study

  - Non-childbearing potential is defined as pre-menarche, current tubal ligation, hysterectomy, ovariectomy or post-menopause.
* Female subjects of childbearing potential may be enrolled in the study, if the subject:

  * has practiced adequate contraception for 30 days prior to first study product administration and
  * has a negative pregnancy test on the day of placebo administration/ vaccination, and
  * has agreed to continue adequate contraception during the entire treatment period and for 2 months after completion of the study.

Exclusion Criteria:

* Known history of HBV infection.
* Previous vaccination against hepatitis B.
* Positive for anti-hepatitis B surface (HBs) antibodies, anti-hepatitis B core (HBc) antibodies, HBsAg, HCV antibodies and/or HIV.
* Any previous administration of vaccine components.
* Use of any investigational or non-registered product (drug or vaccine) other than the study vaccines within 30 days preceding the first study product administration, or planned use during the study period.
* No significant dietary restrictions or life-threatening food allergies.
* Regular use of non steroidal anti-inflammatory drugs within 1 month prior to first study product administration.
* Chronic administration (defined as more than 14 days in total) of immunosuppressants or other immune-modifying drugs within 6 months prior to the first study product administration.. Inhaled and topical steroids are allowed.
* Planned administration / administration of a vaccine not foreseen by the study protocol in the period starting 30 days before the first study product administration and during the entire study period (both Steps), with the exception of the influenza vaccine (pandemic or seasonal) which can be administered \> 21 days preceding or \> 21 days following each placebo/vaccine administration.
* Administration of immunoglobulins and/or any blood products within the last 3 months preceding the first study product administration or planned administration during the study period.
* Any confirmed or suspected immunosuppressive or immunodeficient condition, including HIV based on screening evaluations and on medical history and physical examination.
* History of or current bleeding or coagulation disorder.
* Any known or clinical signs of anaemia or any clinical condition (including vascular disorder) that would preclude frequent blood drawings.
* Poor venous access as assessed at screening by the investigator.
* Blood loss, including blood donation, of more than 300 mL within 90 days before the first study product administration.
* History of or current autoimmune or other immune-mediated disease.
* Any haematological or biochemical level out of normal range before entering into the study, as follows:
* Haemoglobin level \< lower normal limit (LNL).
* Platelet counts out of normal range.
* Alanine aminotransferase \[ALT\] \> upper normal limit (UNL).
* Aspartate aminotransferase \[AST\] \> UNL.
* Creatinine \> UNL.
* c-reactive protein \[CRP\] \> UNL.
* Creatine phosphokinase \[CPK\] \> UNL without any plausible explanation for this abnormality (such as sport activity).

In case of haematological and/or biochemical value out of range for parameters mentioned here above, one re-testing of out of range value may be performed.

* Any acute or chronic, clinically significant disease, as determined by medical history, physical examination or laboratory screening tests.
* Known or suspected reaction or hypersensitivity likely to be exacerbated by any component of the vaccines.
* Acute disease and/or fever at the time of enrolment.
* Subjects with a minor illness (such as mild diarrhoea, mild upper respiratory infection) without fever may, be enrolled at the discretion of the investigator.
* Fever is defined as temperature ≥ 37.5°C for oral route.
* Pregnant or lactating female.
* Recent history of chronic alcohol consumption and/or drug abuse.
* Other conditions that the principal investigator judges may interfere with study findings.