Shingles (Herpes Zoster) is caused by the same varicella virus that causes chicken pox. After a person recovers from chickenpox, the virus stays in the body in a dormant (inactive) state. Although the reasons are not fully understood, the virus can reactivate years later, causing shingles.
Shingles usually starts as a painful rash on one side of the face or body. The rash forms blisters that typically scab over in 7–10 days and clears up within 2–4 weeks.
Before the rash develops, there is often pain, itching, or tingling in the area where the rash will develop. This may happen anywhere from 1 to 5 days before the rash appears.
Most commonly, the rash occurs in a single stripe around either the left or the right side of the body. In other cases, the rash occurs on one side of the face. In rare cases (usually among people with weakened immune systems), the rash may be more widespread and look similar to a chickenpox rash. Shingles can affect the eye and cause loss of vision.
As mentioned above, shingles occurs in people who have had a previous bout of chicken pox. When someone who has had chicken pox is exposed to chicken pox again, it actually provides a natural booster and keeps the varicella virus dormant. It is estimated that one needs to be exposed to chicken pox about every ten years to keep this virus dormant and prevent shingles.
Since the advent of the chicken pox vaccine, there has been a drastic decrease in the number of chicken pox cases. So has the vaccine worked? Yes, but it has come at a costly price. Since there are not usual numbers of cases of chicken pox around, adults are not being exposed to the circulating varicella virus and the number of cases of shingles has skyrocketed.
In fact, since the introduction of the chicken pox vaccine, hospitalization costs for complications of shingles have increased by more than $700 million annually for those over 60 years old.
http://www.ncbi.nlm.nih.gov/pubmed/18999945
Merck, the sole manufacturer of the chicken pox vaccine, conveniently provides a solution to this problem: Zostavax – the shingles vaccine. Of course neither the vaccine for chicken pox nor the shingles come without complications. Click on Vaccines above to see the risks and adverse events for these vaccines.