Evaluation of the Immunogenicity and Reactogenicity of a Pneumococcal Conjugate Vaccine in Healthy Adults

Inclusion Criteria: * Written informed consent for participation in the study; ages between 50 and 80 years at recruitment Exclusion Criteria: * Lack of adequate comprehension of the information sheet, consent form and study nurse's explanation of the study in order to give informed consent. * Current participation in any other clinical trial * Any vaccination in the previous month (except influenza vaccination which can be given at any time during the study) * Prior pneumococcal conjugate vaccine (PNC) * 23 valent pneumococcal vaccine(PPV) in last 5 years * Severe general or local reaction to a previous dose of PNC or PPV * Patients currently immunocompromised as listed in UK Handbook "Immunisation Against Infectious Disease" ed 1996 * Patients who have received intravenous immunoglobulin in the previous month or who will require replacement intravenous immunoglobulin during the period of the study * Patients in whom pneumococcal vaccination (PPV) is currently recommended as per the UK Handbook "Immunisation Against Infectious Disease" * Deferral of vaccination if acute systemic illness or temperature \>38C on day of vaccination