Shingles is a painful viral infection that causes a rash of fluid-filled blisters, typically on one side of the body. It is caused by the varicella-zoster virus (VZV), the same virus responsible for chickenpox. After chickenpox, VZV remains dormant in the nervous system and can reactivate years later to cause shingles. A vaccine is available to help prevent this condition.
Understanding Shingles and the Vaccine’s Role
The shingles vaccine bolsters the body’s immune defenses against the dormant varicella-zoster virus. It stimulates the immune system to produce a robust response, preparing the body to fend off viral reactivation. The current vaccine, Shingrix, is a non-live recombinant subunit vaccine containing glycoprotein E, a viral protein, combined with an adjuvant to enhance the immune reaction. This mechanism helps overcome the age-related decline in natural immunity, boosting antibody production and T-cell responses to maintain strong surveillance against the virus.
The Likelihood of Shingles After Vaccination
Despite the vaccine’s strong protective capabilities, a small percentage of vaccinated individuals can still develop shingles, sometimes called a “breakthrough case.” The Shingrix vaccine demonstrates high effectiveness. For adults aged 50 to 69 with healthy immune systems, it is approximately 97% effective, and for those 70 and older, effectiveness is about 91%. Real-world studies show two doses are about 74% effective against shingles in adults aged 50 and older. This likelihood can vary with age, as immune responses naturally change.
Why Shingles Can Still Occur
Shingles can still occur after vaccination primarily due to individual variations in immune responses. While the vaccine significantly boosts immunity, no vaccine provides 100% protection. Genetic factors, underlying health conditions, or certain medications can influence how effectively an individual responds. For instance, in adults with weakened immune systems, effectiveness ranges from 68% to 91%, depending on the specific condition. The varicella-zoster virus remains latent in the body and can reactivate despite enhanced immunity.
Characteristics of Post-Vaccination Shingles
If shingles occurs in a vaccinated individual, the disease course is typically less severe than in those unvaccinated. Symptoms like rash and pain are often milder, and illness duration is usually shorter. A significant benefit of vaccination, even in breakthrough cases, is the substantial reduction in postherpetic neuralgia (PHN) risk. PHN is persistent nerve pain that can linger for months or years after the rash clears. Studies show the vaccine is highly effective in preventing PHN, with rates around 91% in adults aged 50 and older and 89% in those 70 and older.
The Importance of Vaccination
Despite the small chance of a breakthrough case, the benefits of shingles vaccination are substantial for public health and individual well-being. The vaccine dramatically reduces the risk of developing shingles and the potential for severe symptoms and complications. This includes a significant decrease in the likelihood of developing long-term nerve pain. Healthcare providers consistently recommend vaccination as a highly effective preventive measure. Discussing vaccination with a healthcare provider can help individuals understand how this protection fits into their overall health plan.