[Herpes zoster and postherpetic neuralgia - prevention by vaccination?]

Herpes zoster is caused by reactivation of latent varicella-zoster virus (VZV), which had remained latent in the dorsal root or cranial nerve ganglia since the primary infection. The risk of developing zoster increases significantly with age, the vast majority of zoster cases occuring in persons over 50 years. The most frequent and debilitating complication of zoster in immunocompetent patients is postherpetic neuralgia (PHN). In the absence of antiviral therapy, clinical studies have found up to 30 - 45 % of persons over 60 years of age to experience pain persisting for more than 6 months. Systemic antiviral therapy is able to shorten the healing process of acute zoster and to prevent or alleviate pain and other complications, when given within 72 hours after appearance of the rash. About 20 % of patients older than 50 years continue to have pain six months after appearance of rash, despite antiviral treatment. A live attenuated VZV vaccine was licensed in Europe in 2006 for the prevention of zoster in individuals from the age of 60 years. Findings of a large clinical trial have shown that the zoster vaccine reduced the burden of illness caused by zoster among people 60 years of age or older by 61 % and the incidence of PHN by 67 %. Compared with controls, subjects who received the vaccine were 51 % less likely to develop zoster.