Herpes Zoster: the rationale for the introduction of vaccination in Italy.

Herpes Zoster (HZ) and its main complication, post-herpetic neuralgia (PHN), represent an important public health issue because of their relevant burden within older adult population and the actual suboptimal therapeutic management of the diseases. Incidences of HZ and PHN are comparable all over the world and are closely related with the population age. Epidemiological data collected in Italy about HZ and its complications confirmed the trend registered in North America and Europe. Moreover HZ related burden is exacerbated by a significant economic impact related to both direct and indirect costs. Since 2006 a live, attenuated varicella zoster virus vaccine, that contains VZV Oka strain [Zostavax, Merck & Co., Inc.], was licensed for the prevention of HZ and PHN in adults aged ≥ 60 years. Since 2011, the licensure has been extended to adults between 50 and 59 years. The vaccine has demonstrated a good immunogenicity, efficacy and safety profiles in two pivotal phase III clinical trials and the effectiveness was further confirmed after vaccine licensure. Pharmaco-economic studies concluded that HZ vaccine is cost-effective in most European countries and generally supported the economic value of this vaccination. The vaccine is actually recommended in USA, Canada and several European countries. The opportunity to reduce the burden of these diseases by the recommendation of HZ vaccination have been evaluated and suggested also in our Country and some Regions have been recently introduced the vaccine in their immunization plan. If the good results, already obtained with HZ vaccine in other countries, will be confirmed by these Italian pilot experiences, vaccination programs should be made uniform in all Country in order to ensure an equitable offer of this important preventive tool.