Patient report of herpes zoster pain: Incremental benefits of zoster vaccine live.

INTRODUCTION: Pain following herpes zoster (HZ) can persist for months and negatively impact quality of life. To evaluate the effect of zoster vaccine live (ZVL) on progression of pain following HZ, we conducted a prospective cohort study of HZ cases at Kaiser Permanente Southern California.

METHODS: ZVL vaccinated and unvaccinated members aged ≥60 years with laboratory-confirmed HZ from January 18, 2012 to February 26, 2015 were followed up within 5 days of HZ diagnosis, and at 30, 60, and 90 days after diagnosis. Pain was assessed with the Zoster Brief Pain Inventory (ZBPI) on a 0-10 scale, using cut-points of ≥3, ≥5, and ≥7, with postherpetic neuralgia (PHN) defined as pain ≥3 at 90 days. Log binomial regression was used to estimate adjusted risk ratios (aRRs) and 95% confidence intervals (CIs) associated with pain, comparing vaccinated versus unvaccinated HZ patients.

RESULTS: We interviewed 509 vaccinated and 509 unvaccinated HZ patients. ZVL was associated with significantly lower risks of HZ-related pain at all time-points. The risk of PHN in vaccinated and unvaccinated patients, respectively, was 9.2% and 15.4% (aRR = 0.594, 95% CI: 0.413, 0.854); 2.0% and 4.8% of these patients reported pain ≥7 (aRR = 0.332, 95% CI: 0.153, 0.721). Irrespective of vaccination, the risk of PHN was lower in adults aged <70 years versus those ≥70 years and was similar or lower in females versus males.

CONCLUSION: We used laboratory confirmation of HZ cases and patient survey to show that aside from preventing HZ, ZVL reduced HZ-related pain and prevented PHN among vaccine recipients who experienced HZ. Observational studies will be needed to evaluate long-term effectiveness of the new recombinant zoster vaccine and its benefits in protecting patients against PHN.