Complications of herpes zoster in immunocompetent older adults: Incidence in vaccine and placebo groups in two large phase 3 trials.

BACKGROUND:An adjuvanted herpes zoster (HZ) subunit vaccine, HZ/su, demonstrated high efficacy against HZ and postherpetic neuralgia (PHN) in two randomized, observer-blind, placebo-controlled trials in adults aged ≥50 and ≥70 years (ZOE-50 and ZOE-70, respectively). METHODS:Data from ZOE-50 and ZOE-70 trials were analyzed to evaluate the efficacy of HZ/su against mortality, hospitalizations, and non-PHN complications of HZ including HZ-associated vasculitis, stroke, and disseminated, ophthalmic, neurologic, and visceral diseases. RESULTS:In the pooled ZOE-50/ZOE-70 analysis, 1 of 32 HZ/su recipients (3.1%) and 16 of 477 placebo recipients (3.4%) with a confirmed HZ episode had complications other than PHN. Efficacy against HZ-related complications was 93.7% (95% confidence interval, 59.5-99.9%) in adults aged ≥50 years and 91.6% (43.3-99.8%) in adults ≥70 years. Five HZ-related hospitalizations, all in placebo recipients, and no HZ-related deaths were reported. CONCLUSIONS:HZ/su reduces the risk of HZ-associated complications in older adults (NCT01165177; NCT01165229).