Evaluation of Pneumococcal Vaccine Formulations in Young Adults

Inclusion Criteria: * Subjects who the investigator believes will comply with the requirements of the protocol (e.g., completion of the diary cards, return for follow-up visits) should be enrolled in the study. * A male or female between, and including, 18 and 40 years old at the time of the first vaccination. * Written informed consent obtained from the subject. * Free of obvious health problems as established by medical history, clinical examination and clinical laboratory assessment before entering into the study. * If the subject is female, and of child-bearing potential, she agrees to use adequate contraception and not become pregnant for the duration of the study. Exclusion Criteria: * Previous vaccination against Streptococcus pneumoniae. * 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 \> 7 days preceding or \> 7 days following each vaccine dose (after collection of 7-day safety data). * Bacterial pneumonia within 3 years prior to 1st vaccination. * Invasive pneumococcal disease (IPD) within 3 years prior to 1st vaccination. * Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection. * History of thrombocytopenia or bleeding disorder. * History of reactions or allergic disease likely to be exacerbated by any component of the vaccine. * 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. * Acute disease at the time of enrolment/vaccination. * Physical examination positive for acrocyanosis, jaundice, splenomegaly. * Acute or chronic, clinically significant anaemia, pulmonary, cardiovascular, hematologic , hepatic or renal functional abnormality, as determined by physical examination or laboratory screening tests, at the discretion of the investigator. * Laboratory evidence of haematological abnormalities. * Laboratory evidence of biochemical abnormalities * Administration of immunoglobulins and/or any blood products within the three months preceding the first dose of study vaccine or planned administration during the study period. * Pregnant or lactating female. * Female planning to become pregnant or planning to discontinue contraceptive precautions. * History of chronic alcohol consumption and/or drug abuse. * Other conditions that the principal investigator judges may interfere with study findings.