1956. Persistence of Immune Response and Safety of an Adjuvanted Recombinant Zoster Vaccine in Older Adults Previously Vaccinated with a Live-Attenuated Herpes Zoster Vaccine: End-of-Study Results of a Phase III, Group-Matched, Clinical Trial

BACKGROUND: Herpes zoster (HZ), caused by reactivation of varicella-zoster virus (VZV), typically manifests as a dermatomal rash and can result in complications, such as postherpetic neuralgia. HZ risk increases with age due to age-related decline of immunity. At time of study start, Zoster Vaccine Live (ZVL), containing live-attenuated VZV was recommended for vaccination in adults ≥60 years of age. Efficacy of ZVL declines with time since vaccination and increasing age. We evaluated immunogenicity and safety of Adjuvanted Recombinant Zoster Vaccine (RZV) containing truncated form of VZV glycoprotein E (gE) in adults vaccinated with ZVL ≥5 years before (HZ-PreVac) and ZVL-naïve adults (HZ-NonVac). In October 2017, the Advisory Committee on Immunization Practices recommended revaccination of ZVL recipients with RZV, based on available data, including 1 month (M) post-dose 2 results of this study (M3). Here we present immunogenicity and safety results up to 12 months post-dose 2 (M14). METHODS: In this phase III, multi-center study (NCT02581410), open-label, 2 parallel groups of group-matched adults ≥65 years of age, HZ-PreVac and HZ-NonVac, received 2 RZV doses 2 months apart. Humoral and cellular immune responses were evaluated at various time points up to M14. Solicited and unsolicited adverse events (AEs) were recorded for 7 and 30 days post each dose, respectively. Serious AEs (SAEs), HZ cases and potential immune-mediated diseases (pIMDs) were recorded throughout the study. RESULTS: 215 participants were vaccinated in each group. No apparent differences, in pre-vaccination and persistence values of the anti-gE antibody GMCs (Figure 1) and CD4[2+] T-cell frequencies (Figure 2) were observed between HZ-PreVac and HZ-NonVac, up to M14. No clinically relevant differences in frequencies of solicited AEs, unsolicited AEs or SAEs between the two groups were observed. Six pIMDs (two in HZ-PreVac group and four in HZ-NonVac group), were reported up to M14 (Table 1). [Image: see text] [Image: see text] [Image: see text] CONCLUSION: In both groups, RZV-induced humoral and cellular immune responses persisted above baseline up to M14 at similar levels, irrespective of previous ZVL administration. Safety profile was similar regardless of previous ZVL vaccination. Funding: GlaxoSmithKline Biologicals SA. DISCLOSURES: T. Mrkvan, GSK: Employee and Shareholder, Salary and shares and share options. L. Campora, GSK: Employee and Shareholder, Salary. G. Catteau, GSK: Board Member, Salary. M. Douha, GSK: Employee, Salary. K. Grupping, GSK: Employee, Salary. C. Herve, GSK: Employee, Salary. G. Kalema, GSK: Consultant, Consulting fee. T. Heineman, GSK: Consultant, Employee and Shareholder, Consulting fee and Salary. N. P. Klein, GSK: Investigator, Research support. sanofi pasteur: Investigator, Research support. Merck: Investigator, Research support. Pfizer: Investigator, Research support. Protein Science: Investigator, Research support. MedImmune: Investigator, Research support. Dynavax: Investigator, Research support. H. Lal, GSK: Shareholder, Salary. Pfizer: Shareholder, Salary. L. Oostvogels, GSK: Employee, Salary and stock and stock options. A. Schuind, GSK: Employee and Shareholder, Salary.