Chickenpox Vaccine Not Responsible for Rise in Shingles, Study Says
39 percent increase over 18 years remains unexplained
These findings, published in the Dec. 3 issue of the Annals of Internal Medicine, suggest the chickenpox vaccine isn't related to the increase in shingles, according to Hales.
So what might be responsible for the increase in shingles?
Hales says experts aren't sure. "We really don't know why about one-third to one-quarter of people who've had chickenpox go on to develop shingles over their lifetime while others don't," he explained.
Hales did note that conditions and treatments that can compromise the body's immune system have increased in recent years. "We thought perhaps that might explain the rise," said Hales. "But we selected for people who didn't have any diseases or take any medications that suppress the immune system, and we still saw an increase in shingles."
He said the researchers also thought reported cases of shingles could be increasing because more people might see doctors as exposure to medical knowledge increases. But they found that the incidence of shingles was going up faster than the incidence of other conditions. If the increase in shingles were due to more people going to the doctor, the incidence of other medical disorders would also be rising, Hales said.
In the future, Hales said that because of the chickenpox vaccine, "shingles should be a relatively rare disease." That's because youngsters who are vaccinated will never have had the initial infection with the varicella zoster virus.
In the meantime, people who've had chickenpox should consider getting the shingles vaccine. And that means just about everyone. "Almost 100 percent of people in the U.S. have been affected by varicella zoster," Hales said. The CDC recommends the one-time vaccine for anyone aged 60 or older.
Dr. Kenneth Bromberg, director of the Vaccine Research Center at the Brooklyn Hospital Center in New York City, echoed that recommendation.
"So far, we don't know why there's more shingles. But, there is a vaccine that can prevent it," said Bromberg.
Shingles occurs most often in people older than 50. Early symptoms usually include mild to severe burning or shooting pain on one side of the body or face. Rashes or blisters emerge after that, and pain from shingles can continue for weeks, months or even years.