FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

CHICKENPOX VACCINE MIGHT PROTECT AGAINST SHINGLES, TOO

Question: I've read about the new chickenpox vaccination and wondered if this would give any protection against shingles?

Answer: I think you've posed a very interesting and important question. However, I think I need to back up one step before I answer it.

As you already know, but other readers may not, the varicella-zoster virus (VZV) causes several illnesses. The first exposure to the virus produces chickenpox with its itching, irritated blisters and fever. This common childhood illness usually clears up in a few days. The most prevalent complication is pneumonia, which doesn't happen very often.

Our defense system can't actually kill off the attacking chickenpox virus, it only holds it under control. As the chickenpox sores go away, the virus actually goes into hiding along the nerve pathways a state you can think of as hibernation. When the body's immune system becomes less active, the virus begins to stir again. The weakening of immunity is often simply a natural byproduct of aging, but it can also be caused by diabetes, AIDS other health conditions and the use of some medications.

The shingles blisters are painful and erupt along the course of the infected nerves instead of producing a generalized or "body wide" rash like chickenpox. The nerves of the chest are most commonly involved, but any part of the skin may be so afflicted.

I think some numbers will help you understand the scope of the problem associated with VZV. According to one study, only 6.7 percent of men 17 to 26 years old who entered the Army lacked natural antibodies to this virus. That means 93 percent of young men in our country have had chickenpox. This high percentage may not be exactly the same for young men who don't join the Army or for women, but there is no reason to think that these groups would have greatly different numbers. In short, a huge number of people could be spared the discomfort of chickenpox by the use of the vaccine. But, your astute question asked about the effect of the vaccine on those of us who've had chickenpox and are, therefore, susceptible to developing shingles.

A shot of VZV vaccine like a case of the chickenpox causes the recipient to produce antibodies to the virus. Children usually get high levels of antibodies with one shot while adults require a second one at least one month later for the same level of protection. There is ongoing research to determine if the initial shot or shots will give life-long immunity. It may be that a booster shot will be needed to maintain protection throughout life.

In fact, your question actually addresses the same issue. Does a booster shot of VZV prevent shingles in those who have had a natural infection in childhood? Currently, I can only give you a tentative "yes." The evidence at this point is circumstantial. We know that individuals with low antibody levels to VZV are at increased risk for shingles. We also know the chickenpox shot does successfully increase these protective antibody levels in those 60 and older the age group with the highest risk of shingles. However, we haven't yet been able to study a sufficiently large number of people for a long enough period of time to be certain that this increased antibody count will prevent shingles for most people.

Research to clearly show that the VZV vaccine benefits an older population while simultaneously having very low expense and risk is necessary before it can be routinely recommended. I'd advise you to keep checking about this matter with your family doctor. The Centers for Disease Control, the Food and Drug Administration, and the manufacturer of the VZV vaccine will be keeping the medical community informed as the answers to this interesting question become available.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.