More than 99% of people aged 40 or older in the United States carry the dormant chickenpox virus, also known as the varicella-zoster virus. Shingles is a reactivation of the chicken pox virus and typically occurs after age 50. The risk of developing shingles, a painful condition that causes skin blisters and can have serious complications, increases with age and other health conditions.
“One in three people who have had chickenpox develop shingles in their lifetime,” said Quanhe Yang, Ph.D., lead study author and senior scientist at the Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia. “The Zoster Vaccine Live helps to prevent shingles and reduces the risk for shingles by about 51%. But its effect declines with increased age, about 64% in people 60-69 years, about 41% for ages 70-79 years and about 18% in those 80 years or older.”