Shingles is a painful rash caused by the varicella-zoster virus (VZV), the same virus responsible for chickenpox. After an initial chickenpox infection, VZV remains dormant within the nervous system. This dormant virus can reactivate later in life, leading to shingles. A common concern is whether the shingles vaccine itself can cause this painful condition.
Shingles and Its Vaccines
Shingles, or herpes zoster, occurs when the latent varicella-zoster virus reactivates, typically presenting as a stripe of fluid-filled blisters on one side of the body. This reactivation often happens when the immune system weakens, making individuals over 50 more susceptible. Two primary types of shingles vaccines have been developed: Zostavax, an older vaccine, utilized a live, weakened form of the virus. The newer recombinant zoster vaccine, Shingrix, does not contain any live virus, instead using a non-living component to stimulate an immune response.
Live Attenuated Vaccine and Shingles Risk
The live attenuated shingles vaccine, Zostavax, contained a weakened but living varicella-zoster virus. Because of this, there was a very small, theoretical risk that the vaccine itself could cause a mild, shingles-like rash or symptoms. This rare occurrence was more of a concern for individuals with weakened immune systems, where the weakened vaccine virus might replicate more readily. The Zostavax vaccine is no longer available in the United States, having been discontinued as of November 2020, though it may still be used in some other countries.
Recombinant Vaccine and Shingles Risk
The recombinant shingles vaccine, Shingrix, does not contain any live virus. It is made from a non-living viral component combined with an adjuvant to enhance the immune response. Because it lacks live virus, Shingrix cannot cause shingles. Recipients commonly experience temporary side effects, which are normal indicators that the immune system is building protection. These reactions often include pain, redness, and swelling at the injection site, along with systemic symptoms such as muscle pain, fatigue, headache, shivering, and fever; these symptoms are typically mild to moderate and usually resolve within two to three days.
Balancing the Risk: Why Vaccination is Recommended
Shingles can lead to severe complications, including postherpetic neuralgia (PHN), which causes persistent nerve pain lasting months or years and significantly impacting daily life. Other potential complications include vision loss, neurological issues, and bacterial skin infections. The currently recommended Shingrix vaccine offers over 90% effectiveness in preventing shingles and PHN in adults aged 50 and older. The benefits of vaccination far outweigh the minimal or non-existent risks of vaccine-induced illness. Public health recommendations emphasize vaccination for adults aged 50 and older, and for immunocompromised individuals aged 19 and older, given its high efficacy and favorable safety profile; even individuals who have previously had shingles or received the older Zostavax vaccine are encouraged to get Shingrix for enhanced protection.