Zostavax is a vaccine that is used for preventing shingles in people age 50 and over. The medicine is a live but weakened version of the varicella-zoster virus that causes the body to produce an immune system response. Zostavax is given as a single injection, just under the skin. Potential side effects include headaches and injection site reactions.
What Is Zostavax?
Zostavax® (shingles vaccine) is a single-dose vaccine used to prevent shingles in people 50 years old and older. It is not used to treat an active case of shingles.
Previously, Zostavax was approved only for individuals age 60 and older. However, it is now approved for people as young as 50 years of age.
Who Makes It?
Zostavax is made by Merck & Co., Inc.
How Does Zostavax Work?
Shingles is caused by a virus, the varicella-zoster virus (VZV). The initial infection of varicella-zoster virus causes a case of chickenpox. After the case of chickenpox, the virus never goes away. It remains inactive in certain nerve cells of the body, waiting to become active again (which usually occurs as people age and their immune systems are less able to suppress the virus). Zostavax is a live (but weakened) version of the varicella-zoster virus. It causes the body to produce an immune system response to the virus, which helps prevent shingles.
Effects of Zostavax
Like most vaccines, Zostavax is not 100 percent effective at preventing shingles. Studies have shown than overall, giving the drug to people age 50 and older reduces the chance of shingles by about 50 percent. Like most vaccines, Zostavax is less effective when given to older individuals whose immune systems are less able to produce a response. In people 60 to 69 years old, it prevented 64 percent of cases of shingles, while in people over the age of 80 years old, the drug prevented only 18 percent of shingles cases.
Even when Zostavax does not prevent shingles, it seems to reduce the complications that can occur from shingles, such as chronic pain ("postherpetic neuralgia"), scarring, vision problems, and other problems.