On Mar. 24, 2011, Zostavax, manufactured by Merck of Whitehouse Station, New Jersey, was approved by the U.S. Food and Drug Administration (FDA) to prevent shingles. Zostavax is licensed as a one-dose vaccine for people age 60 years or older.

In the United States shingles affects approximately 200,000 healthy people between the ages of 50 and 59, per year. It is a disease caused by the varicella-zoster virus, which is a virus in the herpes family and the same virus that causes chickenpox. After an attack of chickenpox, the virus lies dormant in certain nerves in the body. For reasons that are not fully understood, the virus can reappear in the form of shingles, more commonly in people with weakened immune systems and with aging.

Zostavax is a live, attenuated vaccine, meaning it is a living organism that has been weakened and adapted to provide immunity without causing illness. Shingles affects an estimated 1 million or more individuals in the U.S. each year – almost half of those cases are among people age 60 or older, for whom zoster vaccine is recommended.