Researchers from the Department of Veterans Affairs have shown that an experimental vaccine against shingles prevented about half (51 per cent) of cases of shingles, a painful nerve and skin infection, and dramatically reduced its severity and complications in vaccinated persons who got shingles, in one of the largest adult vaccine trials.

The medical term for shingles is herpes zoster, and the vaccine was called "zoster vaccine.” The findings appeared in the June 2, 2005, New England Journal of Medicine.

Shingles is characterized by pain in one area of skin on one side of the body or face, and by a painful, blistering rash in the same area of skin. Caused by reactivation of the virus that caused chickenpox, which persists in a dormant state within nerve cells in everyone following this childhood infection, shingles can afflict anyone who has had chickenpox, which includes most adults in the United States. Shingles and a complication called postherpetic neuralgia (PHN), consisting of pain originating in damaged nerves that can persist for months or years, can diminish the quality of life and functional capacity of older adults, and markedly reduce their enjoyment of life.

The Shingles Prevention Study involved more than 38,500 men and women, age 60 or older at 22 study sites across the United States - 16 VA medical centres and six clinical sites outside of the VA system coordinated through the National Institute of Allergy and Infectious Diseases (NIAID). Half of the subjects received a placebo and the other half received a single injection of the zoster vaccine— containing a live, attenuated (weakened) form of varicella-zoster virus, the virus responsible for chickenpox and shingles. The zoster vaccine, manufactured by Merck & Co., Inc., is a new, higher potency version of the vaccine that has been used to prevent chickenpox in children since 1995. The new zoster vaccine was developed for and studied in older adults.

“The zoster vaccine was able to prevent shingles, or convert it to a minor illness,” said Dr. Myron Levin, an infectious disease specialist at the University of Colorado and one of the study’s authors.

The zoster vaccine reduced the incidence of PHN by two-thirds (66 percent) compared to placebo. The researchers emphasized that the zoster vaccine was tested only as a preventive therapy. It is not intended as a treatment for those who already have shingles or postherpetic neuralgia.

The Shingles Prevention Study was a VA Cooperative Study carried out in collaboration with the NIAID and Merck & Co., Inc. The study was funded by the VA and Merck & Co., Inc., which supplied the vaccine and placebo.