What is shingles?

Herpes zoster (also known as shingles) is an infection caused by the same virus that causes chickenpox. Essentially, if you've had the chickenpox, the virus lie dormant in your nerve roots for years. Stress or aging can wake the virus. When that happens, the virus mutates into shingles, characterized by symptoms that include severe pain, nerve damage and a rash on one side of the body. The herpes zoster vaccine (known as Zostavax) can protect against shingles.

Who gets it?

Anyone who has had chickenpox can get shingles later on in life.

What are the side effects?

No serious problems have been linked to receiving the shingles vaccine. Mild problems include redness and soreness at the injection site.

Vaccine recommendation

The vaccine is recommended by the Centers for Disease Control and Prevention for people over the age of 60. In tests, the vaccine reduced shingles incidents by more than 60 percent, and the vaccine is believed to provide immunity for at least six years.

What you need to know

Anyone with a weakened immune system should not get the vaccine. Those groups include people with HIV/AIDS, those undergoing cancer treatment and those who have an active case of tuberculosis.