Herpes zoster vaccination in inflammatory bowel disease: Evidence, guidelines, and reality

Table 2 Epidemiology of herpes zoster in inflammatory bowel disease and general population - herpes zoster in inflammatory bowel disease[10,11,14,16,17,20]

Feature	CD	UC
Overall incidence rate	Higher overall burden (15.9 cases per 1000 PY)	Slightly lower burden (13.6 cases per 1000 PY)
Relative risk (vs non-IBD)	1.66 times to 1.99 times	1.34 to 1.50
Risk in young adults	Dramatic risk increases with an IRR of 3.35 compared to healthy peers	Displays a lower relative risk increase than CD in this age group, with an aIRR of 1.85
Complication risk	High risk for disseminated or visceral disease when heavily immunosuppressed	High risk for complications, though crude incidence rates are generally lower than in CD

IBD: Inflammatory bowel disease; CD: Crohn’s disease; PY: Patient-years; IRR: Incidence rate ratio; UC: Ulcerative colitis; aIRR: Adjusted incidence rate ratio.