First vaccine for shingles gets FDA's OK

Washington -- The Food and Drug Administration approved the sale of a vaccine to reduce the risk of shingles, or herpes zoster, in those older than 60. Caused by the same virus that produces chickenpox, the sometimes excruciatingly painful condition affects an estimated 20% of the nation's population at some time in their lives.

The vaccine, to be marketed as Zostavax, is the first for this disease. The FDA announced its decision May 25.

It should be considered a booster shot that prevents varicella-zoster virus, acquired during a bout of the chickenpox, from re-emerging, said Jesse Goodman, MD, PhD, director of the FDA's Center for Biologics Evaluation and Research, during a briefing. It should not be considered a treatment for shingles, but a preventive step, he said.

Anyone one who has had chickenpox can get shingles. The varicella virus can remain dormant in nerve tissues for decades until risk factors -- such as increasing age and declining immunity -- allow it to resurface. The result is often a sweep of painful blisters along one side of the body. Shingles was named for the Latin cingulum, or girdle.

Although the rash may subside within days, the condition's most dreaded aftermath is chronic pain, or postherpetic neuralgia, and that can last for months or years. Two of every 10 people are affected by shingles in their lifetimes and about half have severe pain, said Dr. Goodman.

"This vaccine gives health care providers an important tool that can help prevent an illness that affects many older Americans and often results in significant chronic pain," he said. The attenuated virus vaccine is given as a single subcutaneous injection, preferably in the upper arm.

It was studied in 38,000 people age 60 and older at 22 trial sites across the country. None of the participants had experienced shingles. Half were given Zostavax and half a placebo. All were followed for about three years to see if they developed the illness and, if so, how long the pain lasted.

Researchers found that the shots reduced the occurrence of the condition by about 50%. Among the vaccinated group there were 315 cases of disease, while the placebo group registered 642. The best results were seen among 60- to 69-year-olds, where the vaccine reduced shingles by 64%.

In addition, people who developed the disease despite being vaccinated experienced less pain, according to the trial results.

The most common side effects of an injection were redness, pain, tenderness and swelling at the site of the injection, itching and headache.

Although these effects were minor, a subset of patients was followed more closely, and signs of more serious health concerns were detected among that group, said Dr. Goodman. For that reason, manufacturer Merck is conducting a postmarketing study to gather additional safety data, he said.

The label points to a slight, but not statistically significant, increase in cardiovascular events in the first 42 days after receiving an injection.

Who should be vaccinated

The vaccine is not advised for people who have had shingles. "Once you have shingles, there is a very low rate of having them again," Dr. Goodman said. In addition, because it is made with a live virus, it is not recommended for people with compromised immune systems, such as those with AIDS or transplant recipients receiving immunosuppressant drugs.

People younger than 60 should also hold off on receiving a shot until additional efficacy and safety data are provided, said an FDA advisory panel that met last winter.

The Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices will provide recommendations as to who should receive a dose, said Dr. Goodman. "In terms of FDA approval, the safety and efficacy of the vaccine was for people age 60 and older. And that is the population that is most likely to get shingles and have severe pain. But we will see how the ACIP looks at these data and then what individual physicians and patients decide."

Exactly how the new vaccine will work in conjunction with the chickenpox vaccine, which is recommended for all children, remains to be seen. Whether people will be less likely to get shingles having been vaccinated against its companion disease or more likely because they received a lesser amount of the virus than they would have with the actual illness is an unknown. "Time will tell what the long-term role of this vaccine will be," said Dr. Goodman.

In the meantime, the new vaccination is being welcomed for the important role it could assume in adult preventive health measures. The hope among promoters of an adult vaccine track is that the new offering will prove a popular draw and entice adults to visit their physicians for annual flu shots as well as pneumococcal injections. "We're used to children's vaccines," said Dr. Goodman. "Now we're seeing the extension of this benefit to the adult population."

Zostavax, which is frozen, is available for ordering, and Merck expects to begin shipping it soon. The cost is $145.35 when purchased as a 10-pack of single-dose vials of lyophilized vaccine with sterile diluent.