2018 Volume 92 Issue 2 Pages 103-114
Two large randomized multinational efficacy trials (ZOE-50 and ZOE-70) showed that the novel herpes zoster subunit vaccine (HZ/su) candidate containing varicella-zoster virus glycoprotein E (gE) and the AS01B adjuvant system reduced the risk of herpes zoster (HZ) and post-herpetic neuralgia (PHN) by more than 90%. We conducted a descriptive subgroup analysis in subjects enrolled in Japan in these studies and evaluated the results.
Participants received two doses of HZ/su or a placebo (assigned in a 1：1 ratio) administered intramuscularly 2 months apart. Vaccine efficacy against HZ was assessed in participants aged ≧50 years in ZOE-50 and in a pooled analyses of participants aged ≧70 years from ZOE-70 and ZOE-50. Vaccine efficacy against PHN was also assessed as a co-primary endpoint. Safety was assessed in all subjects and reactogenicity was assessed in a subgroup of participants. Humoral and cell mediated immunogenicity (CMI) were assessed in the respective subset for which blood samples were collected.
A total of 577 participants from ZOE-50 and 511 participants from ZOE-70 were enrolled in Japan, with a total of 1,042 included in the efficacy analysis (561 and 481 subjects, respectively). Overall vaccine efficacy against HZ in 561 adults ≧50 years was 81.4% (95% confidence interval [CI]：14.9-98.0%). In the pooled analysis of all Japanese ZOE-50 and ZOE-70 participants ≧70 years (N=608), vaccine efficacy against HZ was 92.4% (95% CI：69.4-99.1%). As no PHN event was observed in the HZ/su group, the vaccine efficacy against PHN was 100% (95% CI：-58.7-100%). Vaccine efficacy against HZ and PHN remained high throughout 4 years of the study period. Robust humoral and CMI responses were observed and persisted throughout the study period in HZ/su recipients. Solicited reports of injection-site and systemic reactions within 7 days after injection were statistically significantly more frequent among HZ/su recipients than among placebo recipients. The frequency of serious adverse events, potential immune-mediated diseases, and deaths in the HZ/su recipients was similar to the placebo recipients and no statistically significant difference was found.
Based on above results, it can be concluded that HZ/su has demonstrated high efficacy as well as robust immunogenicity in the Japanese sub-population, in line with the results observed in the global studies. In terms of safety, no meaningful differences were detected between the Japanese population and the global population. HZ/su seems to be a valuable vaccine in Japanese elderly people.
