Safety of the adjuvanted recombinant zoster vaccine in adults aged 50 years or older. A phase IIIB, non-randomized, multinational, open-label study in previous ZOE-50 and ZOE-70 placebo recipients

BACKGROUND: Efficacy of the adjuvanted recombinant zoster vaccine (RZV) against herpes zoster (HZ) was demonstrated in pivotal trials ZOE-50 (NCT01165177) and ZOE-70 (NCT01165229). This study was designed to offer RZV to placebo recipients of these parent studies. METHODS: Vaccine safety and suspected HZ episode occurrence were assessed for 12 months following vaccination. RESULTS: Of the 14,550 eligible participants, 8687 received RZV and 97.8% completed the 2-dose schedule. During the 30-day post-vaccination period, 5175 (59.6%) participants experienced ≥ 1 unsolicited adverse event (AE), 4422 (50.9%) were vaccination-related. The most common AEs were injection-site reactions, pyrexia, and headache. During the study, 734 (8.4%) participants reported ≥ 1 serious AE (SAE) and 62 (0.7%) reported ≥ 1 potential immune-mediated disease (pIMD); 2 of each were assessed as vaccination-related. Suspected HZ episodes were reported by 30 participants (0.3%). CONCLUSIONS: Nature and incidence of AEs, SAEs, and pIMDs were as expected and in line with the parent studies.