The Adjuvanted Recombinant Zoster Vaccine in Adults Aged ≥65 Years Previously Vaccinated With a Live-Attenuated Herpes Zoster Vaccine.

BACKGROUND: Efficacy of the live-attenuated herpes zoster (HZ) vaccine (ZVL) wanes substantially over time. We evaluated immunogenicity and safety of the adjuvanted recombinant zoster vaccine (RZV) in previous ZVL recipients. METHODS: Adults aged >/=65 years previously vaccinated with ZVL >/=5 years before (HZ-PreVac, N=215) were group-matched with ZVL-naive individuals (HZ-NonVac, N=215) and vaccinated with RZV. Glycoprotein E (gE)-specific humoral and cell-mediated immune (CMI) responses and the correlation between them, polyfunctional gE-specific CD4 T-cell responses, safety, and confirmed HZ cases were assessed. RESULTS: Through 12 months post-dose 2, anti-gE antibody concentrations, gE-specific CD4 T-cell frequencies and activation marker profiles were similar between groups. Safety outcomes were also similar. No HZ episodes were confirmed. CONCLUSIONS: RZV induced strong humoral and polyfunctional CMI responses that persisted above pre-vaccination levels through 1 year post-dose 2 in adults aged >/=65 years irrespective of previous ZVL vaccination. RZV's safety profile was not impacted either.