When a vaccine to prevent shingles was approved for use in 2006, the Food and Drug Administration recommended the vaccine for people age 60 and older who previously had chickenpox.

But two issues -- the vaccine's cost and the perception that shingles primarily affects adults with weakened immune systems -- have left some physicians undecided about whether healthy adults need the vaccine.

This uncertainty prompted a group of researchers led by Barbara Yawn, M.D., of Olmsted Medical Center in Rochester, to gather new data about the incidence and impact of shingles in unvaccinated patients.

Published in the November issue of Mayo Clinic Proceedings, Dr. Yawn's research findings suggest that shingles and the complications associated with it may have a greater impact upon healthy adults than most physicians previously assumed.

"The best way to make a decision about who we should vaccinate is by gaining a better understanding about the true impact of this virus," notes Dr. Yawn. "Physicians have access to very few recent studies that tell us how many people in the United States get shingles, what age groups the virus affects most, and how many of these people go on to develop related complications or other problems."

Shingles isn't a life-threatening condition, but it can cause a painful rash or band of blisters during an outbreak and other painful complications that can persist for months or even years.

The goal of this study was to establish accurate, up-to-date data about the incidence and impact of shingles in the United States before the vaccine was introduced. Dr. Yawn and her team recorded the number of adult residents of Olmsted County, Minn., who were diagnosed with shingles and shingles-related complications from Jan. 1, 1996, to Dec. 31, 2001. Over the course of the study, 1,669 patients were included.

Researchers calculated that shingles affects at least 1 in every 278 adults in the United States each year. Study data also showed that shingles is even more common among people ages 50 to 59, affecting about one in every 24 people each year.

"Overall, our data suggests that researchers and physicians also need to consider preventing shingles in people ages 50 to 59," says Dr. Yawn. "Future research is needed to understand the risk of recurrence of shingles to better advise people who previously had shingles about the value of receiving the shingles vaccine."

Dr. Yawn noted that study data also challenged the assumption that shingles primarily affects adults with weakened immune systems.

"More than 92 percent of the study subjects with shingles did not have any conditions like cancer or other serious illnesses that affected their immune system," says Dr. Yawn.

Post-herpetic neuralgia was the most common complication noted, occurring in about 8 percent of all people and increasing with age. This sometimes debilitating complication causes the skin to remain painful and sensitive to touch for months or even years after the rash clears up.

"About 18 percent of people age 80 or older experience pain that lasts more than 90 days beyond the shingles," explains Dr. Yawn.