FDA panel approves vaccine for shingles

Dec 19 2005

According to an FDA advisory panel, studies show that an experimental vaccine to prevent shingles can cut the rate of infection by about half in people 60 and older and help curb related pain.

But drug company Merck's data also showed the vaccine, Zostavax, did not significantly reduce rates of death or hospitalization and became less effective after three years.

The advisory panel of outside health experts say that Zostavax showed no serious side effects and they will consider whether to recommend approval.

The FDA usually follows its advisory panels advice.

Apparently Merck is also seeking approval for another vaccine to help prevent rotavirus, the most common cause of diarrhea in children, and a panel will discuss the product this week.

Shingles is caused by the same virus that triggers chicken pox, the varicella-zoster virus, and is characterized by a wave of small rash-like blisters on the skin.

The virus targets the nerves and can lead to intense pain.

Figures show that as many as 1 million people in the United States develop shingles each year.

Some antiviral drugs can help control the outbreak and prevent the pain, all of which can last for up to five weeks on average.

Other drugs such as antidepressants, steroids and anticonvulsants, also can help decrease the initial discomfort.

According to experts shingles is more prevalent among older people, and more will contract the infection as people live longer.

In their review, the FDA staff also noted age was a factor in how well the vaccine worked, saying it was less effective in people 70 and older.

Viral infections were reduced by 63.9 percent in people 60 to 69 years old, compared with 37.6 percent in those ages 70 and older, say the panel.

Illness-related pain dropped by 65.5 percent in 60- to 69-year-olds and by 55.5 percent in those 70 and older.

In separate documents, Merck officials said Zostavax significantly reduced the incidence of the virus as well as related complications when compared with a placebo.

The vaccine is says Merck, "generally well tolerated" in people age 50 and older.

Merck tested Zostavax in eight clinical trials, including one with 38,546 volunteers age 60 and older, about half of whom received the vaccine, while the others took a placebo.

The results found the vaccine cut the risk of infection in half, with 315 people who received the vaccine developing the painful disease, compared with 642 in the placebo group.

Merck also is seeking European approval for the vaccine.