Shingles Vaccine Being Tested in Adults Over 60

A stronger dose of the chicken-pox vaccine is being tested in elderly adults to see if it can prevent shingles.

Baylor College of Medicine is one of 21 medical centers testing the vaccine as part of a national Veterans Affairs Cooperative Study.

Shingles is a painful skin and nerve infection caused by the varicella-zoster virus, the same virus that causes chicken pox. Most children get chicken pox and recover from the widespread blisters it causes, but the virus then hides out in groups of nerve cells next to the spinal cord. At various times after chicken pox, most commonly in late adulthood, the varicella-zoster virus might reactivate and travel down nerves to the skin, where it causes a painful rash on one side of the body, such as an area of the back, chest, or face.

The shingles rash usually heals within several weeks, but extreme pain from damaged nerves can persist for years. This condition, called postherpetic neuralgia, can be severely debilitating.

"More than half of all cases of shingles occur in patients who are 60 or older, and half of the people who live to age 85 will get the disease," says Dr. Wendy Keitel, principal investigator for the Baylor site. "Although there are effective antiviral medications to treat shingles, patients could be spared the whole ordeal if we had a vaccine to prevent the disease."

Volunteers for the study must be at least 60 years of age and must have had chicken pox or lived in the United States for at least 30 years, which would make them likely to have been exposed to the varicella-zoster virus. People who have already had shingles are not eligible.

"The body develops an immune response to the virus when you get chicken pox, but that immunity declines as people grow older," says Dr. Keitel, associate professor of microbiology and immunology. "The vaccine we're testing was designed to boost the preexisting immunity."

Participants will get either the experimental vaccine or a placebo injection. They will be monitored for up to five years. Any participant who develops shingles during the study will receive free antiviral medication for treatment. If the vaccine proves useful in preventing or reducing the severity of the disease, participants who were given the placebo will be offered the vaccine at the end of the study, much sooner than it will be available to the general public.

Dr. Keitel hopes to enroll 1,800 adults from the Houston area, including patients from the Houston Veterans Affairs Medical Center and Ben Taub General Hospital. Drs. Richard Hamill and Carmel Dyer in Baylor's department of medicine will help recruit patients for the study.

- B. J. ALMOND

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©2006 Texas Medical Center

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