People who received a vaccination for shingles (also known as herpes zoster) but still contracted shingles had a lower risk of developing post-herpetic neuralgia (PHN), a potentially long lasting and painful complication of the condition. The Kaiser Permanente study was published in The Journal of Infectious Diseases.
This study demonstrates that the shingles vaccine can still be beneficial in reducing the risk of long term pain even among those patients for whom it does not prevent the disease.
Shingles is a painful skin rash that affects one in three adults and is caused by the varicella zoster virus, the same virus that causes chickenpox. The most common complication of shingles is PHN, for which treatment for the pain may be necessary for months to years.
For this study, researchers reviewed the medical records of 2,400 Kaiser Permanente Southern California patients over 60 years of age who developed shingles after Jan. 1, 2007. One group of patients received the shingles vaccine, yet developed the condition. The other group of patients did not receive the vaccine. Among the vaccinated patients who developed shingles, 4.2 percent of the women experienced PHN, compared to 10.4 percent of the unvaccinated women who developed shingles. In the group of vaccinated men who developed shingles, 6 percent experienced PHN compared to 5.8 percent of unvaccinated men who developed shingles. Researchers suggested that the gender-related differences may be due to the differences in how men and women seek care for chronic pain.
"Our study found that the shingles vaccine has an added protective benefit of reducing the risk of PHN for a vaccinated individual who still experiences shingles," said Hung Fu Tseng, PhD, MPH, study lead author, Kaiser Permanente Southern California, Department of Research & Evaluation. "This further confirms the importance of shingles vaccination for adults over age 60."
As patients get older, the pain associated with PHN is likely to be more severe and may lead to depression, fatigue, insomnia, altered activities of daily living, and decreased socialization. The estimated annual cost for direct medical care related to shingles is $1 billion in the U.S., according to the CDC.
In 2006, the Food and Drug Administration approved the shingles vaccine and subsequently the Advisory Council on Immunization Practices recommended the vaccine for people 60 years or older. Despite that, vaccination rates remain low.
"Hopefully, this study will encourage more people to get vaccinated in order to reduce the long-term pain and potential disability associated with shingles," Dr. Tseng said.