Herpes zoster is caused by reactivation from previous varicella zoster virus (VZV)
infection, and affects millions of people worldwide. It primarily affects older adults and those with immune system dysfunction, most likely as a result of reduced or lost VZV-specific cell-mediated immunity. Complications include post-herpetic
neuralgia, a potentially debilitating and
chronic pain syndrome. Current treatment of
herpes zoster and post-herpetic
neuralgia involves
antiviral agents and
analgesics, and is associated with significant economic cost. Results from several clinical trials have determined that a live, attenuated VZV
vaccine using the Oka/Merck strain (
Zostavax) is safe, elevates VZV-specific cell-mediated immunity, and significantly reduces the incidence of
herpes zoster and post-herpetic
neuralgia in people over 60 years of age. Regulatory approval has recently been obtained and once launched, it is expected that this
vaccine will significantly reduce the morbidity and financial costs associated with
herpes zoster. Durability of
vaccine response and possible booster vaccination will still need to be determined.