FDA approves Merck vaccine to prevent shingles
Fri May 26, 2006 10:15 AM ET

May 26 - U.S. health regulators on Friday approved the first vaccine to prevent shingles, a painful disease characterized by a blistering rash, the vaccine's developer, Merck & Co. , said.

Shingles is caused by the reactivation of the virus that causes chickenpox, and treatments generally only relieve pain and shorten the duration of the disease. The virus can lie dormant after childhood and strike again when the immune system weakens with age or illness.

The U.S. Food and Drug Administration approved the vaccine, Zostavax, for people aged 60 and older. The company also plans to seek approval for those as young as 50.

Everyone who has been infected with chickenpox -- about 90 percent of American adults -- is at risk of developing shingles, Merck said.

"This is going to be one of our important products," said Christine Fanelle, a Merck spokeswoman. "We have a lot of plans to make it a big success."

The vaccine is given as a single dose by injection, and Merck plans to charge $145.35 per dose.

There are roughly 50 million Americans over the age of 60, the vast majority of whom would be eligible for the vaccine, Merck said.

Cowen and Co. analysts in a March report had estimated sales of Zostavax could reach $900 million by 2010.

An FDA advisory panel in December had recommended approval of the vaccine for those 60 and over, but did not recommend it for younger adults because there was no data on the vaccine for adults aged 50 to 59.

"We'll be working with the FDA to talk about an indication beginning at age 50 and what it is specifically the FDA would like to see in addition," said Dr. Jeffrey Silber, Merck's senior director of clinical research, in an interview.

Symptoms of the disease can begin with a pain or tingling on one side of the body, followed by a blistering rash that can last several weeks. Treatment often involves use of antiviral drugs to relieve pain and shorten the duration of the disease.

In some cases the rash is followed by nerve pain known as postherpetic neuralgia that can last weeks or even months and years.

Of the roughly 1 million cases of shingles that occur in the United States each year, 40 percent to 50 percent affect people over the age of 60, the company said.

Merck studied the vaccine in more than 40,000 people, of whom about 21,000 received the vaccine. Zostavax reduced the risk of developing shingles by 51 percent, compared with placebo.

In those people who did develop shingles, the incidence of postherpetic neuralgia was cut by 39 percent, Merck said.

Merck's shares rose 28 cents, or nearly 1 percent to $34.67 in early trading on the New York Stock Exchange.