Vaccine Helps Prevent Chickenpox from Re-emerging as Shingles

If you had chickenpox as a child and think all that nasty itching and redness is gone forever, think again. Although you won't have another outbreak of chickenpox, the virus that caused it remains in your body, and for some of us, it can re-emerge - as shingles.

Shingles is an outbreak of rash or blisters on the skin that is caused by the varicella zoster virus - the same virus that causes chickenpox. According to the National Institute of Neurological Disorders and Stroke (NINDS), "Anyone who has had chickenpox is at risk for shingles. Scientists think that in the original battle with the varicella zoster virus, some of the virus particles leave the skin blisters and move into the nervous system," where they remain dormant for years.

"Shingles occurs when our immunity to the varicella virus reactivates in a discrete region of the skin, generally among people 50 or older," says John J. W. Fangman, MD, an Assistant Professor of Medicine (Infectious Diseases) at the Medical College of Wisconsin. "It can be quite painful, even to a gentle touch." Dr. Fangman sees patients at the Froedtert & Medical College Infectious Disease Clinic.

Pain, Itching and Blisters
Shingles pain can be mild or intense, according to NINDS. The first sign is often burning or tingling pain, or sometimes numbness or itch, in one particular location on only one side of the body. After several days or a week, a rash of fluid-filled blisters, similar to chickenpox, appears in one area on one side of the body. The most common location for shingles is a band called a dermatome, spanning one side of the trunk around the waistline, Dr. Fangman says.

The pain can last from a few days, to weeks, months or even a year, long after the rash has disappeared. According to the Centers for Disease Control and Prevention (CDC), an estimated 1 million cases of shingles are reported in the United States each year.

Shingles can be contagious to people who've never been exposed to chickenpox if they touch someone whose shingles blisters had broken open, Dr. Fangman notes.

Who's at Risk for Shingles?
About 10% to 20% of people who had childhood chickenpox will develop shingles, Dr. Fangman notes, and about 4% will experience a second episode. In addition to people over 50, others at risk for shingles are those with weakened immune systems from diseases like HIV/AIDS, or those who are receiving cancer treatments that can weaken their immune systems. Others with compromised immune systems include people who have had organ transplants and are taking immunosuppressive drugs. For those patients, shingles can lead to widespread skin infections and neurological problems, both serious and potentially life-threatening.

Patients with shingles often get relief from steroids such as prednisone or antiviral drugs like acyclovir, valacyclovir, or famcyclovir, which can shorten the duration of the condition. Drugs used to treat nerve pain can also be helpful in some cases, Dr. Fangman says.

Vaccine Now Available
Since most American adults were exposed to chickenpox, is there any way to avoid developing shingles?

In 1997, a shingles vaccine was developed; it's similar to the chickenpox vaccine given to infants and children, but in a higher dose, Dr. Fangman says. The vaccine, called Zostavax, was approved by the Food and Drug Administration in 2006, and is available to reduce the risk of shingles in people 60 and older. The vaccine is given as a single injection under the skin, preferably in the upper arm.

Zostavax was extensively tested before it received FDA approval. According to FDA Consumer magazine, the vaccine was extensively studied in about 38,000 individuals 60 and older throughout the United States. The studies were double-blind, that is, half the participants received the Zostavax vaccine, and half received a placebo (an inactive substance used as a control in medical testing of pharmaceutical products). All study participants were then followed for an average of three years to see whether they developed shingles and, if they did, how long the pain lasted.

At the conclusion of the study, researchers found that, overall, the vaccine reduced the occurrence of shingles by about 50% in people 60 and older, and by as much as 64% in those between 60 and 69. And for those who did develop shingles despite being vaccinated with Zostavax, it also slightly reduced the duration of pain after its onset.

As the FDA Consumer article noted, the most common side effects in people who received Zostavax "were redness, pain and tenderness, swelling at the site of injection, itching and headache." Some participants reported "significant adverse events" after their injection. However, researchers found that those effects were reported in about the same numbers among both those who received the vaccine and those who received the placebo.

Dr. Fangman recommends that most adults 60 and older ask their doctors about the vaccine, unless they have had shingles previously or have weakened immune systems. "It's generally quite safe," he says. He adds that the vaccine is recommended by the CDC's Advisory Committee on Immunization Practices (ACIP).

Barbara Abel
HealthLink Contributing Writer

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.