Safety, Tolerability, and Efficacy Study of Prophylactic S. Pneumoniae Vaccine Following Challenge With S. Pneumoniae

Inclusion Criteria: * Males and non-pregnant females, ages 18 to 55 years inclusive. * Willing and able to provide written informed consent. * Fluent English speakers only (for safety reasons) * Willing to perform and comply with all study procedures including attending clinic visits as scheduled. Exclusion Criteria: * Prior vaccination with pneumococcal vaccine. * History of invasive pneumococcal disease (i.e., sepsis, meningitis or pneumonia with bacteremia). * Close contact with at risk individuals (young children \[under 5years\], immunosuppressed adults, elderly, chronic ill health). * Current smoker or significant smoking history (\>10 pack years). * Pregnant or breast-feeding woman. * Women of child-bearing potential (WOCBP) who are deemed not to have sufficient, effective birth control in place for 1 month prior to vaccination and 1 month after the final vaccination. * Allergy to penicillin or amoxicillin. * Any screening laboratory value \> Grade 1 * Positive serologic test for HIV-1 or hepatitis C infection; positive hepatitis B surface antigen (HBsAg). * Asthma (on regular medication) or other respiratory disease. * Immunocompromised individuals, including those receiving corticosteroids or other immunosuppressive agents. * Presence or history of auto-immune disease (refer to Appendix 4) regardless of current treatment. * No antibiotic treatment within 1 week of inoculation * Previous involvement in EHPC study inoculated with pneumococcal bacteria * In any other clinical trial unless in observational stage or follow-up * Diabetes, type 1 or type 2. * Other active, uncontrolled co-morbidities that, in the opinion of the Investigator would make the subject unsuitable for the study or unable to comply with the study requirements. NOTE: Subjects who are taking a medication to control an underlying co-morbidity may be enrolled if there have been no changes to their medication within 60 days prior to first dose of Study Drug.