Shingles, also known as herpes zoster, is a viral infection that causes a painful rash. It arises from the reactivation of the varicella-zoster virus (VZV), the same virus responsible for chickenpox. After a person recovers from chickenpox, VZV remains inactive within nerve tissue. The virus can reactivate later in life, leading to shingles.
Understanding Shingles Prevalence
Shingles is a common condition, with about one in three people in the United States experiencing it during their lifetime. Annually, approximately one million cases of shingles occur in the U.S. The annual incidence rate of shingles ranges from two to nine cases per 1,000 people. This risk increases significantly with age, with rates rising from about 6 per 1,000 people aged 50-59 to 15 per 1,000 people aged 70-79.
Factors Influencing Shingles Risk
The primary reason VZV reactivates is a decline in the immune system’s ability to keep the virus dormant. Aging is the most significant factor, as the immune system naturally weakens over time, a process known as immunosenescence, allowing the inactive virus to become active again. The risk of shingles approximately doubles with each decade after age 50.
Other factors that can compromise the immune system and increase shingles risk include certain medical conditions. Diseases such as HIV/AIDS, cancer, and diabetes can weaken the body’s defenses. Medical treatments like chemotherapy, radiation, or medications that suppress the immune system, such as those used after organ transplantation or corticosteroids, also elevate the risk. While less common, severe physical trauma or emotional stress can potentially trigger VZV reactivation.
Preventive Measures
Vaccination is an effective method to reduce the likelihood of developing shingles. Current recommendations suggest that adults aged 50 and older receive the shingles vaccine. The vaccine works by boosting the immune system’s specific response against the varicella-zoster virus, helping to maintain its dormant state and reduce viral reactivation.
The vaccine not only lowers the risk of getting shingles but also decreases the severity of symptoms and the likelihood of long-term complications, such as postherpetic neuralgia, if shingles does occur. It is administered in two doses, two to six months apart, for optimal effectiveness. Even individuals who have previously had shingles can benefit from vaccination to prevent future occurrences.