Zostavax is a live vaccine developed by Merck & Co. which has been shown to reduce the incidence of herpes zoster (known as Shingles) by 51.3% in a pivotal phase III study of 38,000 adults aged 60 and older who received the vaccine. The vaccine also reduced by 66.5% the number of cases of postherpetic neuralgia and reduced the severity and duration of pain and discomfort associated with shingles, by 61.1%. In some cases, Zostavax can actually cause shingles.

Zostovax was approved by the FDA in May, 2006 . The FDA recommended it only for adults aged 60 who meet the following requirementshttp://www.fda.gov/CBER///label/zosmer052506pi.pdf:

• Has not had a life-threatening allergic reaction to gelatin, the antibiotic neomycin, or other component of the herpes zoster vaccine.
• Does not have a weakened immune system due to HIV/AIDS or another disease or medications (such as steroids, radiation and chemotherapy) that affect the immune system.
• Does not have a history of cancer affecting the bone marrow or lymphatic system, such as leukemia or lymphoma.
• Does not have active, untreated tuberculosis.

On October 25th, 2006, the CDC's Advisory Committee on Immunization Practices (ACIP) voted to recommend that Zostavax be given to all adults age 60 and over, including those who have had a previous episode of shingles .