Estimating the Public Health Benefits of Preventing Herpes Zoster and Postherpetic Neuralgia in Greece by Zoster Vaccines: A Modelling Study

OBJECTIVES: Herpes zoster (HZ) imposes a considerable burden to adults ≥50 years of age (YoA) and substantial healthcare and societal costs. Greece’s national HZ vaccination program covers adults 60-75 YoA, with the Zoster Vaccine Live (ZVL). An Adjuvanted Recombinant Zoster Vaccine (RZV) can also be used to prevent HZ. This study aimed to translate the efficacy of RZV into potential long-term public health and economic benefits for the Greek setting, for populations ≥50 YoA.

METHODS: Α mathematical model was populated with epidemiological and clinical efficacy evidence from the literature and clinical trials, to project the potential long-term clinical and economic benefits of fully vaccinating the ≥50 YoA population with RZV and to compare the projected effects of RZV and ZVL.

RESULTS: Vaccinating N=1,000,000 immunocompetent and immunocompromised adults ≥50 YoA with RZV would prevent 107,585 HZ cases, 24,389 postherpetic neuralgia (PHN) cases, and 13,179 other complications over their lifetime. Reduction in healthcare utilization is estimated at 593,616 physician visits and 5,578 hospitalizations. Averted direct costs and productivity losses are estimated at €26.3 million and €12.7 million, respectively. RZV’s number needed to vaccinate (NNV) to prevent one HZ case is estimated at 8, 8, 10, 12, and 21 for the age groups 50-59, 60-64, 65-69, 70-79, and ≥80 YoA, respectively. For the same age groups, ZVL’s NNV to prevent one HZ case is estimated at 41, 31, 30, 58, and 249, respectively. Compared to ZVL, RZV is expected to prevent additional 85,983 and 17,999 HZ and PHN cases, respectively, corresponding to €28 million savings. Persistent economic gains were estimated for ≥60 and ≥70 YoA cohorts and the current universal mass vaccination cohort (60-75 YoA) in Greece.

CONCLUSIONS: RZV vaccination is predicted to avert a significant number of HZ and PHN cases, thus resulting in substantial public health benefits and averted costs.