Vaccine cuts risk of shingles: study

NEW YORK (Reuters Health) -- Older adults who had the shingles vaccine were half as likely to develop the painful condition than unvaccinated adults in a new study. The results suggest the vaccine could prevent tens of thousands of shingles cases each year if it were offered to everyone who is eligible, the authors say.

Shingles is a rash that may be accompanied by severe pain, and is caused by the same virus that causes chickenpox. Studies suggest that about 25 percent of people may suffer from shingles at some point in their lives, and older adults are most at risk. Most shingles cases go away with medication, but occasionally patients continue to feel pain for months afterwards.

In 2006, the U.S. Food and Drug Administration approved a vaccine against shingles, made from a weakened form of the chickenpox virus, for adults over age 60.

While the vaccine had been tested before, its effectiveness hadn’t been measured under the real-world conditions in regular doctors’ offices, where researchers couldn’t control who got the vaccine and how carefully it was handled. “We didn’t know how well the vaccine actually performed in the community setting,” lead author Hung Fu Tseng, a research scientist at Kaiser Permanente in Southern California, told Reuters Health.

To figure that out, Tseng and his colleagues compared about 75,000 members of the health care organization who got the vaccine with a group of about 225,000 similarly aged members who weren’t vaccinated. Everyone in the study was at least 60 years old, and the researchers didn’t include people for whom the vaccine is not recommended -- such as those with HIV, leukemia or lymphoma.

Using electronic health records, the researchers were able to track which patients were diagnosed with shingles over a period that covered anywhere between six months and three years after some of them were vaccinated.

According to the results, published in the Journal of the American Medical Association, about six out of every 1,000 people who were vaccinated got shingles each year. In comparison, 13 of every 1,000 unvaccinated patients in the study were diagnosed with shingles each year. The researchers calculated that for every 71 people who were vaccinated, one case of shingles was prevented.

Because they did not follow patients over the long term, the researchers don’t know how effective the vaccine is years later, when its effects may start to wear off.

Some of the authors reported previously having received research funding from Merck, the company that markets the vaccine.

Despite the FDA’s approval, the shingles vaccine has not yet caught on as much as some had hoped. Because there are about 50 million adults over age 60 in the U.S., the vaccine has the potential to prevent many cases of the uncomfortable and potentially serious condition, the researchers say. Another risk with shingles is that people with the condition can pass the virus on to others in the form of chickenpox.

“The human cost of (shingles) is enormous,” Dr. Michael Oxman, who studies infectious diseases at the University of California, San Diego, and was involved in a previous study on the vaccine, told Reuters Health. But, he said, “Adult medicine is really geared toward diagnosis and treatment of existing diseases. The adult medical community is just not as attuned to preventing disease ... as pediatricians are.”

There’s also the cost to consider. The vaccine is covered under all Medicare Part D prescription drug plans, but not by Part B plans covering doctor visits and other medical services, and co-pays vary. For people whose insurance doesn’t cover it, the vaccine can cost up to $200.

In addition, “the vaccine actually requires stringent storage and handling practices, so that may also affect the efficacy” if doctors don’t adhere closely to those practices, Tseng said.

People who get the vaccine sometimes report side effects including swelling, itching and headaches.

But doctors studying the vaccine say that the cost and potential side effects are worth it, although more research is needed. Tseng said that use of the vaccine is “increasing, but still low” and that current research findings should encourage doctors to discuss the vaccine with their older patients.

Oxman said that many researchers don’t take into account the human suffering that accompanies shingles. But this study, he said, “takes a real population and demonstrates that the vaccine provides medical value in that patient population.”

SOURCE: Journal of the American Medical Association, online January 11, 2010.