Impact of Herpes Zoster Vaccine on Postherpetic Neuralgia: A Comprehensive Review

Background: Herpes zoster (HZ), also known as shingles, is often complicated by postherpetic neuralgia (PHN), a chronic pain condition that significantly impairs quality of life. Vaccination against HZ has become a key preventive strategy to lower the risk of PHN. This review evaluates the effectiveness of HZ vaccines in reducing the incidence of PHN. Methods and Results: In accordance with PRISMA guidelines, a systematic search was conducted across PubMed, Embase, Web of Science, and the Cochrane Library up to May 2024. Eligible studies included randomized controlled trials (RCTs), cohort studies, and observational studies that reported quantitative outcomes on the occurrence of PHN after vaccination. The included studies encompassed diverse populations, primarily older adults. The recombinant zoster vaccine (RZV) demonstrated a substantial reduction in PHN incidence, with effectiveness approaching 60%. In contrast, the live zoster vaccine (ZVL) showed notable early protection, though its efficacy declined over time. The recombinant zoster vaccine (RZV) was associated with higher rates of mild, self-limiting adverse reactions compared with ZVL. Conclusions: Both HZ vaccines, particularly RZV, are effective in preventing PHN and exhibit acceptable safety profiles. Broader vaccine uptake could decrease the public health burden of PHN. Long-term data on the duration of immunity and the potential role of booster doses remain areas for future investigation.