Getting vaccinated against shingles may do more than just prevent a painful rash—it could also help lower the risk of developing dementia. A recent study involving over 280,000 older adults found that those who received the shingles (herpes zoster) vaccine were 20% less likely to be diagnosed with dementia compared to those who didn’t get the shot.
“If the shingles vaccine truly helps prevent or delay dementia, this would have major implications for clinical care, public health, and dementia research,” said Dr. Pascal Geldsetzer, senior author of the study and assistant professor of medicine at Stanford University.
A Natural Experiment in Wales
The research leveraged a unique vaccination program launched in Wales on September 1, 2013, which unintentionally created two comparable groups: individuals eligible for the vaccine (those who turned 79 on or after that date) and those ineligible (those who had already turned 80 before the cutoff).
This design allowed researchers to compare outcomes between nearly identical populations—differing only in whether they received the vaccine—mimicking the structure of a randomized clinical trial.
The study reviewed the health records of individuals aged 71 to 88, all of whom were dementia-free at the start of the program. The researchers focused on those who turned 80 just before and just after the eligibility cutoff, ensuring that both groups were matched in key characteristics such as overall health, education, and healthcare access.
Significant Results Over Seven Years
Published in the journal Nature, the findings revealed that those vaccinated had a 20% lower likelihood of receiving a dementia diagnosis over a seven-year follow-up period.
Interestingly, the protective effect was more pronounced in women than in men. Dr. Geldsetzer suggested this could be due to differences in immune system responses or in the biological pathways of dementia. “Women generally have stronger antibody responses to vaccines, and both shingles and dementia are more prevalent in women,” he noted.
What is Shingles?
Shingles is caused by the varicella-zoster virus—the same virus that causes chickenpox. After a person recovers from chickenpox, the virus remains dormant in the body. It can reactivate later in life, particularly in older adults or those with weakened immune systems, leading to shingles. This reactivation can result in nerve inflammation, severe pain, and other complications, some of which may contribute to neurological damage.
Final Thoughts
While more research is needed to fully understand the link between shingles vaccination and dementia prevention, this study adds compelling evidence in favour of widespread vaccination in older adults. As scientists continue to explore potential causes and preventions for dementia, simple and already-available tools like vaccines may play a larger role than previously expected.
