Shingles is caused by the same virus that causes chickenpox. After a person recovers from chickenpox, the virus stays dormant in the body. For unknown reasons, the virus can reactivate years later, causing shingles.

Zostavax®, the shingles vaccine, reduced the risk of shingles by 51% and the risk of post-herpetic neuralgia by 67% based on a large study of more than 38,000 adults aged 60 years or older. Protection from shingles vaccine lasts about 5 years.

While the vaccine was most effective in people 60 through 69 years old, it also provides some protection for people 70 years old and older.

Adults vaccinated before age 60 years might not be protected later in life when the risk for shingles and its complications are greatest.