Vaccine sharply cuts risk of shingles in seniors, study finds

LOS ANGELES — A study of more than 300,000 elderly patients showed the underutilized herpes zoster vaccine reduced the incidence of painful shingles outbreaks by 55 percent, even in the oldest populations, researchers reported Tuesday.

The results suggest the vaccine, which was introduced in 2006 and now reaches only about 11 percent of the elderly population nationwide, should be used much more widely, experts said.

Shingles is a painful rash brought on by the varicella zoster virus, which is also the virus that causes chickenpox. Once chickenpox subsides, the virus can remain hidden in a person's body for decades before erupting once more.

In addition to pain, a rash can cause vision loss if it spreads to the eyes. The most severe complication is post-herpetic neuralgia, in which the virus causes irritation and inflammation inside nerves. That is a persistent, painful condition that can go on for years and is "extremely challenging to control," said Dr. Bruce Hirsh, an infectious-diseases specialist at North Shore University Hospital in Manhasset, N.Y., who was not involved in the research. "Some patients have even been driven to suicide."

The herpes zoster vaccine, sold as Zostavax by Merck, was introduced in an attempt to prevent such complications.

Epidemiologist Hung Fu Tseng of Kaiser Permanente's department of research and & evaluation in Pasadena, Calif., and his colleagues examined the records of 75,761 vaccinated and 227,283 unvaccinated male and female members over the age of 60 from 2007 to 2009. Among those who were not vaccinated, there were 13 cases of shingles for every 1,000 people, but only 6.4 cases among those who were vaccinated.

That means one case of shingles was prevented for every 71 people vaccinated, they reported in the Journal of the American Medical Association.

The original clinical trial that led to the vaccine's approval of the vaccine found that it was not as effective in people over the age of 75, but Tseng's results found that age did not make any difference. "That's still a mystery to us," he said. "It will need more study."

The Centers for Disease Control and Prevention now recommends the vaccine for all people over the age of 60 unless they are immune-suppressed, have leukemia or lymphoma, are HIV-positive or are allergic to any of the components of the vaccine. The agency is thought to be considering recommending lowering the recommendation to age 50.