Immunogenicity and Safety of a Live Attenuated Zoster Vaccine (ZOSTAVAX™) in Korean Adults

Abstract

A live attenuated zoster vaccine (ZOSTAVAX™, Merck & Co., Inc.) was approved by the Korea Ministry of Food and Drug Safety in 2009. However, the immunogenicity and safety of the vaccine has not been assessed in Korean population. This is multi-center, open-label, single-arm study performed with 180 healthy Korean adults ≥ 50 yr of age. The geometric mean titer (GMT) and geometric mean fold rise (GMFR) of varicella zoster virus (VZV) antibodies were measured by glycoprotein enzyme-linked immunosorbent assay (gpELISA) at 4 weeks post-vaccination. Subjects were followed for exposure to varicella or herpes zoster (HZ), the development of any varicella/varicella-like or HZ/HZ-like rashes, and any other clinical adverse experiences (AEs) for 42 days post-vaccination. For the 166 subjects included in the per-protocol population, the GMT at Day 1 was 66.9. At 4 weeks post-vaccination, the GMT for this population was 185.4, with a GMFR of 2.8 (95% CI, 2.5-3.1). Of the 180 subjects vaccinated, 62.8% experienced ≥ 1 AE, with 53.3% of subjects reporting injection-site AEs. The most frequently reported injection-site AEs were erythema (45.0%) with the majority being mild in intensity. Overall, 44 (24.4%) subjects experienced ≥ 1 systemic AE, 10 (5.5%) subjects experienced a systemic vaccine-related AE, and 3 (1.7%) subjects experienced ≥ 1 serious AE not related to vaccine. No subjects reported a VZV-like rash. There was no subject of death and no subject discontinued due to an adverse event. A single dose of zoster vaccine induced VZV-specific gpELISA antibody response and was generally well-tolerated in healthy Korean adults ≥50 yr of age (registry at www.clinicaltrial.gov No. NCT01556451).

Keywords: Adverse Effects; Aged; Herpes Zoster Vaccine; Humans; Immunology; Republic of Korea.

Conflict of interest statement

DISCLOSURE: This work was supported by Merck Sharp & Dohme Corp. (sponsor), a subsidiary of Merck & Co., Inc. This study was designed, executed, and analyzed by the sponsor. Although the sponsor reviewed a draft, the opinions expressed are those of the authors and may not necessarily reflect those of the sponsor. All co-authors approved the final version of the manuscript.

Figures

Fig. 1. Inverse Cumulative Distribution of Varicella-zoster Virus (VZV) Antibody Titer in the per-protocol (PP) group. VZV glycoprotein enzyme-linked immunosorbent assay (gpELISA) antibody titers (units/mL) were observed clearly increased after the vaccination with ZOSTAVAX™ in the PP group.

Fig. 2. Inverse cumulative distribution of glycoprotein enzyme-linked immunosorbent assay (gpELISA) fold rise at 4 weeks post-vaccination according to the age group.