Dementia
One Reason I Got the Shingles Vaccine—And Why You Should, Too
Recent studies show the shingles vaccine might protect your brain against dementia.
Posted May 12, 2025 Reviewed by Michelle Quirk
Key points
- Shingles causes severe nerve pain and can lead to long-term complications.
- New research suggests the shingles vaccine may lower dementia risk.
- Getting vaccinated is a simple step to protect both nerve and brain health.
I recently reached the age when my primary care doctor recommended that I get the shingles vaccine. As a physician, I know shingles is a painful and debilitating disease and that the vaccine works. But the real reason I got vaccinated will probably surprise you: The vaccine likely protects against dementia. Here’s what we know and don’t know.
What Is Shingles?
Shingles—also known as herpes zoster—is a condition caused by the same virus that causes chickenpox (varicella zoster virus). Long after you recover from the fever and blisters from chickenpox, the virus stays hidden in the body. The virus is able to infect nerve cells and sit silently inside them.
As people age or their immune systems weaken, the virus reactivates inside these nerve cells. People with shingles develop an excruciatingly painful rash that tracks along the path of the nerve in which the virus lies dormant. In some cases, shingles leads to pain and tingling that can last for months to years, a condition called post-herpetic neuralgia.
People who have gotten the chickenpox vaccine can also develop shingles, but at much lower rates than someone who was infected with the actual virus. The vaccine is made from a strain of the virus that is weakened but still has the ability to hide in the nerves and re-activate later.
Shingles is common, occurring in about one in three people in the United States during their lifetime. Because the risk increases with age, the Centers for Disease Control and Prevention currently recommends that adults 50 years and older get the shingles vaccine.
How Does the Shingles Vaccine Work?
The shingles vaccine, Shingrix, is classified as a recombinant vaccine. That means it is the combination of a protein from the virus and another substance that helps boost the immune response. Together, these help stimulate the body’s immune system to recognize and fight off the herpes zoster virus before it can reactivate. Clinical trials show that Shingrix is more than 90 percent effective at preventing shingles (more than 80 percent in real-world studies), making it one of the most effective vaccines available for older adults.
Could the Shingles Vaccine Protect Against Dementia?
It may surprise people that a vaccine that protects against a rash could also protect your memory and thinking ability. But there are a lot of reasons why this is plausible.
First, research increasingly shows that inflammation plays a critical role in neurodegenerative diseases like Alzheimer’s. Chronic infections and reactivation of viruses can trigger low levels of inflammation in the brain, potentially contributing to cognitive decline.
Of the many viruses humans get infected with, herpes zoster is particularly concerning because it infects nerve cells and can even invade the brain, leading to encephalitis or brain inflammation. It is possible that neurons in the brain die because of the virus itself or because of the body’s immune reaction to fighting the virus—kind of like innocent bystanders in a shootout.
The shingles vaccine may reduce dementia risk in two ways:
- Direct protection against viral reactivation: By preventing shingles, the vaccine reduces episodes of inflammation and nerve damage that could contribute to cognitive decline.
- “Off-target” immune benefits: Some vaccines stimulate immune responses that provide broader protection against other infections and inflammatory processes, which could help protect brain health.
What Does the Evidence Say About the Shingles Vaccine and Dementia?
Multiple studies have been published in the past five years indicating that the vaccine may prevent dementia. One reason to believe these findings is that they showed consistent results across different populations, using different study designs, by different teams of researchers. One reason to remain skeptical is that none of these were randomized controlled trials, which is considered the gold standard for medical evidence.
In the past two years, we have had two high-quality studies using real-world data (although not randomized controlled trials) to add to the evidence that the shingles vaccine likely protects against dementia.
A study from 2024 analyzed data from more than 200,000 patients in the United States. It found that people who received the Shingrix vaccine had a 17 percent lower risk of dementia than those who received the older vaccine. They estimated that this was equal to about 164 days of life without dementia. One particular strength of this study is that it controlled for one important form of bias in previous studies by comparing people who got an older version of the shingles vaccine to a newer version.
A second study, published this year, analyzed data from Wales comparing patients who did and did not receive the vaccine due to a strict age cutoff in insurance coverage. They found a 20 percent reduction in dementia in patients who received the vaccine. This study was particularly strong because it controlled for other important factors—such as medications, other vaccines, and health care—and it replicated the findings using a different dataset of patients from England.
Does Shingles Vaccine Prevent Alzheimer's?
In addition to Alzheimer's disease, patients may develop dementia due to several other health conditions. Other common causes of dementia include vascular dementia, which is due to repeated small strokes; Parkinson's disease; and traumatic brain injury.
One question these studies have not yet fully answered is whether the vaccine protects against all types of dementia or just Alzheimer's.
Should You Get the Shingles Vaccine?
The most compelling reason to get the shingles vaccine remains its proven ability to prevent a painful, potentially debilitating illness. Shingrix is safe, widely available, and strongly recommended for adults over 50.
While we don’t yet have definitive proof that the vaccine also prevents dementia, the evidence suggests it will likely help, and it certainly won’t hurt. As I age, my priority is not just living longer but also keeping my brain sharp. Given how devastating dementia is and the possibility of benefit, getting vaccinated was an easy decision for me.
For those eligible, I strongly encourage discussing the shingles vaccine with your doctor. It’s a small step that has the possibility of making a big difference—not just for avoiding shingles but also for keeping your brain healthier for years to come.