DOI: https://doi.org/10.36347/sasjm.2026.v12i11.007

Pages: 1175-1185

Background: Herpes zoster (HZ) is a growing public health concern, with accumulating evidence of increased incidence and severity in the post-COVID-19 era. The recombinant zoster vaccine (RZV) has demonstrated high efficacy in randomised trials, but its broader impact on health-related quality of life (HRQoL), safety, and mortality particularly amid pandemic-related immune perturbation and health-system disruption requires systematic quantification. Methods: We systematically reviewed randomised controlled trials (RCTs), cohort studies, and case-control studies published between January 2017 and October 2025 that evaluated RZV in adults (≥18 years) and reported HZ incidence, postherpetic neuralgia (PHN), HRQoL, safety, or mortality. Random-effects models were used for pooling. Pre-specified subgroup analyses examined immune status, age, and study design. Certainty of evidence was graded using GRADE. Results: Of 3,458 records identified, 116 full texts were assessed and 27 publications representing 18 primary studies (3 RCTs, 15 observational studies; >2.1 million participants) were included. RZV efficacy against HZ was 94.7% (95% CI 93.0–96.0) in immunocompetent adults ≥50 years in RCTs and 81.0% (95% CI 74.0–86.5) in observational studies. In immunocompromised adults, RZV reduced HZ incidence by 81% relative to placebo (RR 0.19, 95% CI 0.09–0.44). Protection against PHN was 84.7% (95% CI 60.9–94.0) in immunocompetent and 38.7% (95% CI 19.1–53.5) in immunocompromised populations. Efficacy was durable, at 82.0% (95% CI 63.0–92.2) in the eleventh-year post-vaccination. RZV reduced the HZ burden of illness and interference with activities of daily living by >90%, and improved HRQoL among breakthrough cases. Reactogenicity was higher than placebo, but serious (RR not significant) and fatal adverse events (RR 0.88, 95% CI 0.61–1.04) were not increased. RCTs showed no short-term mortality difference (RR 0.94, 95% CI 0.84–1.04), whereas observational studies suggested a 39