Evaluation of Pneumococcal Vaccine Formulations in Elderly

Inclusion Criteria: * Subjects who the investigator believes will comply with the requirements of the protocol should be enrolled in the study. * Male or female subjects between, and including, 65 and 85 years old at the time of the first vaccination, in relatively stable health. * Written informed consent obtained from the subject. Exclusion Criteria: * Previous vaccination against Streptococcus pneumoniae (with a licensed vaccine or with an investigational candidate vaccine). * Vaccination with diphtheria/tetanus toxoids within one month preceding the first dose of study vaccine. * Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine(s) within 30 days preceding the first dose of study vaccine, or planned use during the study period or participation to another pharmaceutical/vaccine study. * Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose. * Planned administration/administration of a vaccine not foreseen by the study protocol within 30 days of the first dose of study vaccine, with the exception of the influenza vaccine which can be administered at least 7 days preceding or at least 7 days following any vaccine dose. * Administration of immunoglobulins and/or any blood products within the last 3 months. * Bacterial pneumonia within 3 years prior to 1st vaccination. * Invasive pneumococcal disease (I.P.D) within 3 years prior to 1st vaccination. * History of thrombocytopenia or bleeding disorder. * Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection. * History of reactions or allergic disease likely to be exacerbated by any component of the vaccine. * History of administration of an experimental/licensed vaccine containing MPL or QS21. * Current serious neurologic or mental disorders. * Inflammatory processes such as known chronic active infections (e.g. Hepatitis B, C). * All past or current malignancies (excluding non-melanic skin cancer) and lymphoproliferative disorders diagnosed or treated actively during the past 5 years. * Acute disease at the time of enrolment. * Physical examination positive for acrocyanosis, jaundice, splenomegaly * Acute or chronic, clinically significant anaemia, pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by history, physical examination or laboratory screening tests at the discretion of the investigator. * Laboratory evidence of haematological abnormalities. * Laboratory evidence of biochemical abnormalities. * History of chronic alcohol consumption and/or drug abuse. * Other conditions that the principal investigator judges may interfere with study findings.