Abstract
OBJECTIVE: The protection duration of herpes zoster (HZ) vaccination is unclear among patients with autoimmune (AI) diseases. METHODS: Using 2006-2013 Medicare data, HZ vaccinated patients with AI were matched 1:2 to unvaccinated HZ. Incidence rates (IR) and adjusted risk ratios over time were calculated using Poisson regression. RESULTS: Of 59,627 vaccinated patients, crude IR increased from 0.75/100 person-years during the first year post-vaccination to 1.25 during the seventh year. Vaccinated patients had a significantly lower risk of HZ compared with the unvaccinated through 5 years. CONCLUSION: HZ vaccination was significantly protective only for about 5 years among patients with AI.