Efficacy And Serious Adverse Events Profile Of The Adjuvanted Recombinant Zoster Vaccine In Adults With Pre-Existing Potential Immune-Mediated Diseases: A Pooled Post Hoc Analysis On Two Parallel Randomized Trials

Objective. In the ZOE-50 (NCT01165177) and ZOE-70 (NCT01165229) phase 3 clinical trials, the adjuvanted recombinant zoster vaccine (RZV) demonstrated >= 90% efficacy in preventing herpes zoster (HZ) in all age groups >= 50 years. Given the increased HZ risk associated with certain underlying autoimmune diseases or their treatment regimes, we conducted a post hoc analysis of RZVs efficacy against HZ and safety profile [specifically, the occurrence of serious adverse events (SAEs)] in ZOE-50/70 participants who reported pre-existing potential immune-mediated diseases (pIMDs) at enrolment and were not on immunosuppressive therapies.Methods. Adults aged >= 50 (ZOE-50) and >= 70 (ZOE-70) years were randomized to receive two doses of RZV or placebo 2?months apart. In this subgroup analysis of participants with at least one pIMD at enrolment, the efficacy was calculated for two-dose recipients who did not develop confirmed HZ before 30 days post-dose 2. SAE occurrence was evaluated for all participants who received at least one dose.Results. Of the 14645 RZV and 14660 placebo recipients from the ZOE-50/70 studies, 983 and 960, respectively, reported at least one pre-existing pIMD at enrolment and were included in these analyses. The most frequent pre-existing conditions were psoriasis, spondyloarthropathy and RA. Efficacy against HZ was 90.5% (95% CI: 73.5, 97.5%) overall with the lowest being 84.4% (95% CI: 30.8, 98.3%) in the 7079-year-old age group. SAEs and fatal SAEs were similar between RZV and placebo recipients.Conclusion. In ZOE-50/70 participants with pre-existing pIMDs, RZV was highly efficacious against HZ and SAE incidence was similar between RZV and placebo recipients.