Inclusion Criteria:

1. Males and females over the age of 18 with inflammatory bowel disease; healthy controls will be age- and sex-matched.
2. The patient must understand and voluntarily sign and informed consent document
3. A history of chronic (greater than 1 month) ulcerative colitis or Crohn's disease diagnosed and documented by the standard clinical, radiographic, endoscopic, and histopathologic criteria
4. (Group 1): Outpatients at CSMC IBD center with IBD who are on maintenance anti-TNF therapy with infliximab OR ADALIMUMAB plus concomitant immunomodulator therapy (with either 6MP, AZA, or MTX)
5. (Group 2): Outpatients at CSMC's IBD Center with documented IBD who are not on any immune-suppressive medications. Treatment with oral or topical 5-ASA products, antibiotics, or probiotics, are permitted.
6. (Group 3): Healthy volunteers without chronic illness, not on immune-suppressive medications.

Exclusion Criteria:

1. Hypersensitivity to any component of the vaccine
2. Current signs or symptoms of severe, progressive or uncontrolled renal, hepatic, hematologic, endocrine (including thyroid), pulmonary, cardiac, infectious, neurologic or cerebral disease. Included are ongoing chronic active conditions such as chronic active hepatitis.
3. Patients who in the judgment of the investigator are unwilling or unable to comply with all the protocol-related assessments and procedures.
4. History of alcohol or other drug abuse within one year, or any conditions associated with poor compliance.
5. Patients in whom venipunctures are not feasible due to poor tolerability or lack of easy access.
6. Healthy volunteers or patients with a history of prior pneumococcal vaccination
7. Any condition which, in the opinion of the Investigator, places the patient at unacceptable risk if he/she were to participate in the study.