Recombinant Zoster Vaccine Uptake and Risk of Flares Among Older Adults With Immune‐Mediated Inflammatory Diseases in the US

OBJECTIVE: Persons with immune-mediated inflammatory diseases (IMIDs) are at an increased risk of herpes zoster (HZ). In 2018, the Centers for Disease Control and Prevention recommended a highly efficacious vaccine, recombinant zoster vaccine (RZV), for prevention of HZ in immunocompetent patients ≥50 years of age. This study was undertaken to estimate RZV vaccination among adults ages ≥50 years with IMIDs during 2018-2019 and to examine possible vaccine-related flares following RZV. METHODS: We identified a cohort of IMID patients using medical claims data from the IBM MarketScan (ages 50-64 years) and Centers for Medicare and Medicaid Services Medicare (ages ≥65 years) databases. Presumed flares were defined as hospitalization/emergency department visit for their respective IMIDs, or steroid treatment with a short-acting oral glucocorticoid or parenteral glucocorticoid injection. We conducted a self-controlled case series (SCCS) analysis to examine a temporal association between RZV and flares. RESULTS: Among enrollees with IMIDs, 14.8% of 55,654 MarketScan enrollees and 43.2% of 160,545 Medicare enrollees received ≥1 dose of RZV in 2018-2019. Two-dose series completion rates were 76.6% in MarketScan enrollees and 85.4% in Medicare enrollees. In the SCCS analysis, 10% and 13% developed flares in the control window, compared to 9% and 11-12% in the risk window following 1 or 2 doses of RZV among MarketScan and Medicare enrollees, respectively. We found no statistically significant increase in flares following RZV administration for any IMID in either age group following RZV dose 1 or dose 2. CONCLUSION: We did not find an increase in presumed flares following RZV vaccination. Among adults ages ≥50 years with IMIDs, a substantial proportion received RZV compared to general zoster coverage estimates, and series completion rates were high.