Background/Purpose: Herpes zoster (HZ) vaccine is recommended for healthy people age >= 60 years in US. It is unclear whether the absolute risk for younger patients (pts) with autoimmune or inflammatory (AI) diseases is high enough to warrant vaccination. We evaluated the overall and age-stratified absolute incidence of HZ infection associated with different AI diseases compared to healthy older adults who are recommended for vaccination by the CDC.

Methods: Using 2007-2010 Multi-Payer Claims Database, we assembled 7 AI disease cohorts, requiring pts to have ≥ 13 months continuous medical and pharmacy coverage. Pts with at least one prescription and two diagnoses of rheumatoid arthritis (RA), psoriasis arthritis (PsA), psoriasis (PsO), ankylosing spondylitis (AS), inflammatory bowel disease (IBD), lupus (SLE), gout were included and compared with diabetic pts and healthy pts without diabetes or any autoimmune disease. We identified HZ using diagnosis codes and antiviral agent +- 30 days. Age-adjusted incidence rates (AAIR) and age-specific rates for HZ per 1,000 person-years were calculated for each disease and compared to healthy older people age 60-69 using Poisson regression.  Based upon external data, we used a non-inferiority margin of an HZ IR ratio (IRR) of 0.62 to establish non-inferiority of HZ rates of younger pts with AIs versus healthy older people. Rates were classified as significantly higher (bold) if the lower limit of the IRR 95% CI >1, comparable (i.e. non-inferior, bold, underlined) if the lower limit of the IRR 95% CI > 0.62 but ≤ 1, or inconclusive.

Results: The study population consisted of 50,646 pts with RA, 2629 with PsA, 4299 with PsO, 1,019 with AS, 7,916 with IBD, 8,395 with SLE, 5893 with gout, 214,631 with diabetes and 330,727 in the healthy cohort. The AAIRs among the 7 disease cohorts ranged from a high of 14.6 per 1,000 person years (SLE) to a low of 5.0 (gout). AAIR was 5.9/1000 for diabetes and 3.9/1000 for healthy cohort. The age-specific rate of HZ for RA, IBD and SLE pts in the 20s, 30s, and 40s, was non-inferior or significantly greater than the corresponding rate in healthy people individuals age >=60 (Table, bold). Compared with the healthy cohort, the adjusted HR for RA (1.4, 95% CI: 1.2-1.5), Gout (1.4, 1.2-1.5), IBD (1.8, 1.5-2.1) and SLE (2.1, 1.8-2.4) were increased significantly.

Conclusion: RA, IBD and SLE are associated with an increased risk of HZ infection compared to healthy people. Based on absolute risk compared to healthy people age >= 60, RA, IBD and SLE patients age >30 may benefit from vaccination for HZ.