The Role of Neutrophils in the Age-driven Decline in Anti-pneumococcal Vaccine Responses

Inclusion Criteria: * Both sexes * Have not been vaccinated with any licensed or experimental pneumococcal vaccine * Ages 21-40; and ≥65. Individuals \>60 years old will also be recruited in case we find no unvaccinated people ≥65 years old * Free of acute infections within the last 2 weeks * Did not take any anti-inflammatory medicine in the last week * Did not ingest alcohol in the last 24 hours * Ability and willingness to provide consent Exclusion Criteria: * Previous vaccination with any licensed or experimental pneumococcal vaccine * Known hypersensitivity to vaccination and vaccine components * Immune deficiency * Use of immune-modulating or suppressive drugs * Malignancies within the last 2 years * Known hematological, rheumatic and inflammatory diseases * Known chronic infections * Poorly controlled chronic cardiovascular and metabolic conditions * Pregnancy * Dementia