Patients with inflammatory bowel disease (IBD) will be assessed for immunologic response to pneumococcal vaccination. Patients with IBD meet criteria as outlined by the Centers for Disease Control (CDC) for pneumococcal vaccination, yet the investigators have found that pneumococcal vaccination in this population is under-utilized. It is unknown whether or not IBD or IBD-related medications impact the immune response to this recommended vaccine.||Three groups of 25 patients each will be recruited. The first group will consist of outpatients with IBD who are receiving infliximab (Remicade TM) while on concommitant immunosuppressive therapy (with either 6MP, azathioprine, or methotrexate). This group is intended to represent a common 'heavily immunosuppressed' patient group with IBD.||The second group will consist of patients with IBD seen in our outpatient clinic who are not on any immune-suppressive medications. These patients meet CDC criteria for vaccination by virtue of having a chronic medical illness. The third group will consist of healthy age-matched (to the first group) controls.||After obtaining informed consent, patients will be screened with baseline lab tests including testing for antibodies against pneumococcus. At the baseline visit, patients will also undergo a brief medical history, physical examination, and assessment of their IBD disease activity.||Included patients will then undergo a one-time intramuscular vaccination with 23-valent polysaccharide pneumococcal vaccine (Pneumovax TM). One month later, subjects will return for a blood draw to assess for response to pneumococcal vaccination.