Shingles, also known as herpes zoster, is a common viral infection. Those who have experienced this painful condition frequently wonder if a past infection provides lasting protection from future episodes. Understanding the nature of the virus and the body’s immune response helps clarify the likelihood of recurrence.
Understanding Shingles
Shingles is caused by the varicella-zoster virus (VZV), the same virus responsible for chickenpox. After chickenpox, VZV remains inactive within nerve tissues for many years.
Reactivation of this latent virus leads to shingles, typically presenting as a painful, blistering rash. This outbreak usually appears as a distinct stripe of blisters on one side of the body, often on the torso or face. The exact reasons for reactivation are not always clear, but a decline in immune system function often plays a role.
The Reality of Recurrence
Having experienced shingles does not provide lifelong immunity against future episodes. While a prior infection can temporarily boost the immune system’s response to VZV, this protection is not absolute or permanent.
Studies indicate that approximately 1.2% to 9.6% of individuals may experience recurrent shingles. This rate can be higher, up to 18%, in people with compromised immune systems. The time between outbreaks can vary widely, with some recurrences happening years after the initial episode.
Several factors can increase the likelihood of shingles recurring. A weakened immune system, whether due to aging, certain illnesses, or medications, is a significant contributor. Risk factors for recurrence include:
Being over 50 years old
Being female
Having autoimmune diseases like lupus or rheumatoid arthritis
Conditions such as cancer (leukemia, lymphoma), HIV, or diabetes
Experiencing postherpetic neuralgia (persistent nerve pain after the rash clears)
High levels of stress
Protecting Against Shingles
Vaccination offers the most effective method for reducing the risk of shingles and its potential recurrence. The recombinant zoster vaccine, Shingrix, is the primary vaccine available. It is recommended for adults aged 50 years and older, and for immunocompromised adults aged 19 years and older.
Even individuals who have previously had shingles should receive the vaccine to help prevent future episodes. It is generally advised to wait until the shingles rash has completely cleared before getting the first vaccine dose. The Shingrix vaccine is administered as a two-dose series, with the second dose typically given two to six months after the first. For those who are immunocompromised, the second dose can be given sooner, between one and two months after the first.
Clinical trials have shown that Shingrix is highly effective, providing 97% protection against shingles in healthy adults aged 50 to 69 years, and 91% protection in healthy adults aged 70 years and older. For immunocompromised individuals, the vaccine’s efficacy ranges from 68% to 91%. This protection has been demonstrated to remain high for at least seven to ten years after vaccination. Vaccination also significantly reduces the risk of developing postherpetic neuralgia, a common complication of shingles.