Merck & Co’s investigational shingles vaccine, Zostavax, not only reduces the incidence of the virus, but also significantly reduced associated the pain burden and can lead to a significant reduction in the incidence of persistent nerve pain, according to new clinical trial data.

More than 38,500 men and women aged 60 and over were included in the Phase III study, which was published in the current issue of The New England Journal of Medicine, with approximately half receiving Zostavax, and the other half receiving placebo. The results specifically showed that Zostavax reduced the incidence of the virus by 51%, and cut the total burden of pain and discomfort caused by shingles by 61%. Merck’s vaccine also reduced the incidence of persistent nerve pain – the most frequent complication of shingles, also known as postherpetic neuralgia – by 67%, and reduced the incidence of shingles by 51%.

Shingles is caused by the reactivation of the virus that causes chicken pox, which lies dormant in the body and can affect anyone who has had chickenpox. It can also lead to complications including persistent nerve pain, which can last for months or even years, Approximately 25%-50% of patients older than 50 years of age develop chronic pain after shingles.

Merck has filed Zostavax with both the US Food and Drug Administration and the European Union [[03/05/05g]].