Shingles Reactivation
Yes, shingles (herpes zoster) absolutely can and does reactivate—this is actually the fundamental nature of the disease. Shingles is not a new infection but rather a reactivation of the varicella-zoster virus (VZV) that has remained dormant in sensory ganglia following primary chickenpox infection, typically from childhood 1, 2.
Understanding the Reactivation Process
The virus establishes lifelong latency in dorsal root and cranial sensory ganglia after primary varicella infection and reactivates when cell-mediated immunity declines 1, 3. This reactivation mechanism explains why:
- Over 95% of adults in developed countries are at risk since they harbor latent VZV from prior chickenpox infection 2
- Age is the primary risk factor, with approximately 50% of individuals aged 80 years or older experiencing at least one episode of shingles 2
- Up to 25% of all individuals will develop herpes zoster during their lifetime 2
Key Triggers for Reactivation
The virus reactivates when immunity wanes, specifically through 1, 3:
- Advancing age (most common trigger due to age-related decline in cell-mediated immunity)
- Immunosuppression from HIV infection, chemotherapy, malignancies, or chronic corticosteroid use 3
- Immunosuppressive medications including JAK inhibitors, TNF inhibitors, and other biologics 1
- Stress factors such as ultraviolet light exposure, fever, psychological stress, and menstruation 1
Can Shingles Reactivate Multiple Times?
Yes, recurrent episodes of herpes zoster can occur, though this is less common 1. The evidence shows:
- A small proportion of patients develop recurrent zoster, particularly those who are immunocompromised 1
- Antiviral prophylaxis should be considered in individuals who experience recurrent episodes 1
- Each reactivation episode can be frequent, painful, long-lasting, and disfiguring, especially in immunocompromised patients where episodes are typically longer and more severe 1
Clinical Implications of Reactivation
When VZV reactivates, it travels along sensory nerves to cause 3, 4:
- Dermatomal distribution of vesicular rash, typically unilateral
- Burning pain that often precedes the rash by several days
- Peak viral shedding within the first 24 hours after lesion onset 5
- Risk of postherpetic neuralgia (PHN), which can persist for months to years after rash resolution 2, 3
Special Considerations for Chromosomally Integrated HHV-6
While the question focuses on shingles (VZV), it's worth noting that chromosomally integrated HHV-6 (CIHHV-6) can theoretically reactivate, though this is extremely rare and requires viral culture plus genome sequencing to confirm 1. This is distinct from typical VZV reactivation and primarily relevant in hematopoietic stem cell transplant recipients.
Prevention of Reactivation
The recombinant zoster vaccine (Shingrix) is strongly recommended for adults aged 50 years and older to prevent reactivation, regardless of prior shingles episodes 6, 5. This vaccine is preferred over the live-attenuated vaccine and has demonstrated significant efficacy in reducing both herpes zoster incidence and PHN 1, 6.
Important caveat: Antiviral medications like acyclovir do not eradicate latent virus—they only control active replication during reactivation episodes 5, 7. The virus remains dormant in ganglia indefinitely, maintaining the potential for future reactivation throughout life.