Comparison of Immuno, Reacto and Safety of Recombinant Hepatitis B Vaccine With or Without MPL in Healthy Older Adults

Inclusion Criteria: * Healthy male or female subjects between 50 and 70 years old. * Written informed consent will have been obtained from the subjects. * Good physical condition as established by physical examination and history taking at the time of entry Exclusion Criteria: * Positive titres for anti hepatitis antibodies * Any vaccination against hepatitis B in the past. * Any previous administration of MPL * Elevated serum liver enzymes at two subsequent determinations 14 days apart. * History of significant and persisting hematologic, hepatic, renal, cardiac or respiratory disease. * Axillary temperature \> 37.5°C at the time of injection. * Any acute disease at the moment of entry. * Chronic alcohol consumption. * Any treatment with immunosuppressive or immunostimulant therapy. * Any chronic drug treatment, which in the investigator's opinion, precludes inclusion into the study. * History of allergic disease likely to be stimulated by any component of the vaccine. * Administration of any other vaccine(s) or any immunoglobulin during the study period. * Simultaneous participation in any other clinical trial.