"The vaccine is really just a triple dose of the chickenpox vaccine," says Donald H. Gilden, MD, chair of the department of neurology at the University of Colorado School of Medicine in Denver. He says that it doesn't seem to have any significant risks. "The minor side effects included things like itching and redness," he says, "and they were more than outweighed by the benefits."
It's unclear how long the vaccine's effects will last. Gilden believes that its immunity may last decades. Dworkin is less sure.
"All we know is that it protects people for four to five years," he tells WebMD. "In the long run, people might need booster shots. We don't know yet."
Who Needs the Vaccine?
While anyone can get shinglesshingles, it's most common in older people. Over half of all cases are in people who are over 60. The older a person is, the higher the risk of problems.
"About 40% of people 60 and older who get shingles go on to have lasting nerve pain caused by PHN," says Gilden. "And that rises to almost 50% in people 70 or older."
The FDA approved the Zostavax vaccine for people who are 60 or older. Its decision was based largely on the vaccine's impressive results in a study published in the New England Journal of Medicine in June 2005. This study tracked a group of 38,000 people over 60, with a median age of 69. Researchers found that the vaccine cut the odds of getting shingles by 50%.
However, despite the FDA's decision, the vaccine still might be used by some doctors in people under 60. This would be called an "off-label" use. Merck, the vaccine's manufacturer, had hoped to get it approved for people 50 or older. And Gilden says that people from age 50-59 are indeed at increased risk.
"People who are 50-59 account for one out of seven cases of shingles," he tells WebMD. "That's a lot." But since the vaccine hasn't been studied in the 50-59 age group, FDA approval is unlikely any time soon, says Dworkin.
Another unanswered question is whether the vaccine is safe for younger people at risk for shingles because of a weakened immune system. This would include people who have had transplants, cancercancer treatments, or are living with HIV or other illnesses.
"There are a lot of people looking at this question," says Dworkin. "I think we'll start getting answers in the next three to five years."