Inflammatory bowel disease (IBD) patients under the age of 50 can have a greater risk than the general population above age 50. IBD patient are commonly treated with immunosuppression that increases the risk for Herpes Zoster. A new HZ vaccine is available that could decrease the risk of HZ in IBD patients.

Inflammatory bowel disease (IBD) is a group of chronic inflammatory disorders of the gastrointestinal tract. A recent national survey from the CDC estimates that the prevalence of IBD in the United States (US) is nearly 3.1 million cases. IBD is often associated with debilitating symptoms, hospitalizations, decreased quality of life, frequent procedures and/or surgery. Treatment options include immunosuppressive therapies, such as corticosteroids, immunomodulators (thiopurines and methotrexate) and anti-tumor necrosis factor alpha (TNF) agents. Although they are effective in achieving clinical remission and decrease the risk of complications, they also increase the risk for serious infections, including herpes zoster (HZ).

The primary goal is to study those patients with IBD who are thought to be at the highest risk for HZ reactivation by evaluating cell mediated immunity (CMI) to VZV.

Inclusion Criteria:

A history of chronic (greater than 3 month) ulcerative colitis or Crohn's disease diagnosed and documented by the standard clinical, radiographic, endoscopic and histopathologic criteria.

3.12 Ages 40-55 3.13 There will four groups divided by medication group. All patients will be on stable doses of medication for at least 3 months divided in the following groups: A) Group A (24 patients): mesalamine therapy or no IBD therapy B) Group B (12 patients): Thiopurine group: On azathiopurine at least 2.0mg/kg or 6MP 1.0mg/kg C) Group C (12 patients): Anti-TNF therapy group: On maintenance therapy infliximab (at least 8 every 8 weeks), golilumab (at least monthly), adalilumab (at least every 2 weeks), or certolizumab (at least monthly) D) Group D (12 patients): Combination therapy: On anti-TNF therapy as described in group along with either 15mg of methotrexate or azathioprine at least 1.0mg/kg or 6MP 0.5mg/kg 3.14 Previous history of varicella infection verified by positive VZV IgG test. 3.15 The patient must understand and voluntarily sign the informed consent document.

3.16 All participants must have received a tetanus, diphtheria, pertussis (Tdap) or tetanus, diphtheria (Td) within the previous 10 years the Wisconsin Immunization Registry (WIR), will be accessed via the EMR, so confirming immunization will not be a limitation) because tetanus CMI will be used as an experimental control.

Exclusion Criteria:

3.21 Current use of systemic steroids 3.22 Other autoimmune condition (e.g Rheumatoid arthritis, autoimmune hepatitis) 3.23 Receipt of HZ vaccine (As above, via WIR) 3.24 History of cytopenia in the last 12 months (WBC < 3.0 or anemia Hgb <10). (All patients on immunosuppressants routinely obtain blood work every 3-6 months, so this will be available at study entry) 3.25 History of previous herpes zoster infection.

IBD patients with confirmed IBD