Chickenpox and shingles are common conditions. While chickenpox is often associated with childhood, shingles typically occurs later in life, raising a common question: can someone develop shingles if they have never had chickenpox?
The Varicella-Zoster Virus
Both chickenpox and shingles are caused by the varicella-zoster virus (VZV). Initial VZV exposure usually results in chickenpox, a contagious disease characterized by an itchy rash with fluid-filled blisters. After a person recovers from chickenpox, the VZV does not leave the body. Instead, it enters the nervous system and remains inactive, or dormant, in nerve cells.
Later, this dormant virus can reactivate. When VZV reactivates, it travels along nerve pathways to the skin, causing the painful rash and blisters characteristic of shingles. This reactivation is typically triggered by a decline in the immune system’s ability to keep the virus suppressed. Shingles is a recurrence of the virus already present in the body, not a new infection.
Developing Shingles Without Chickenpox
While shingles typically arises from the reactivation of VZV after a previous chickenpox infection, it is possible for someone who never had chickenpox to develop shingles. This occurs because shingles results from VZV exposure, not necessarily a prior active chickenpox illness. If an individual is exposed to VZV for the first time, and their immune system does not mount a typical chickenpox response, the virus can still establish latency in nerve cells.
In rare instances, this initial VZV exposure, rather than leading to a chickenpox rash, might directly result in shingles. This is particularly relevant for individuals with compromised immune systems, who may not effectively clear the initial viral exposure or establish latency without a full primary infection. Additionally, exposure to a high viral load could potentially influence the outcome of a first VZV encounter. The key factor is the initial presence of the varicella-zoster virus in the body, which can happen through direct infection or, in some cases, even through the chickenpox vaccine, which contains a weakened form of the virus. People who receive the chickenpox vaccine can still develop shingles later in life, though it is much less likely than after a natural infection.
Factors Increasing Shingles Risk
Several factors can increase a person’s risk of developing shingles. The most significant factor is increasing age; the risk of shingles rises considerably after age 50, with about half of all cases occurring in adults 60 or older. This is due to the natural weakening of the immune system that occurs with aging.
A weakened immune system from other causes also increases shingles risk. This includes conditions such as HIV/AIDS, cancer, and organ transplants. Certain medications can also suppress the immune system, such as steroids, chemotherapy drugs, and immunosuppressants. Significant physical or emotional stress may also weaken the immune system, potentially contributing to VZV reactivation.
Protecting Against Shingles
Vaccination is the most effective way to protect against shingles and its complications. The recombinant zoster vaccine (RZV), Shingrix, is recommended for adults 50 and older, regardless of prior chickenpox or shingles. This two-dose vaccine, given 2 to 6 months apart, provides strong protection.
Two doses of Shingrix are over 90% effective at preventing shingles in healthy adults 50 and older. The vaccine also significantly reduces the risk of postherpetic neuralgia (PHN), a common complication causing long-term nerve pain. Adults 19 and older with weakened immune systems are also recommended to receive two doses of the recombinant zoster vaccine. While vaccination is the primary preventive measure, a healthy lifestyle can support overall immune function.