Brain Health Education Series.
Over the past few weeks you may have seen news reports about a new shingles vaccine (Shingrix) becoming available in South Africa. Most of the coverage has focused on how well it prevents shingles, a painful condition that becomes more common with age. But many of the headlines have also mentioned something rather unexpected: could the vaccine reduce the risk of dementia?
It is an intriguing question, and one that has attracted considerable attention from researchers around the world.
The short answer is that recent studies suggest the answer may be yes. However, the full story is a little more nuanced than many of the headlines imply.
Why are scientists interested?
Shingles is caused by the same virus that causes chickenpox. After recovering from chickenpox, the virus does not disappear completely. Instead, it remains dormant within the nervous system and can reactivate many years later, causing shingles.
Although shingles is best known for its painful rash, doctors have long recognised that it can affect the nervous system in other ways. In some people it may inflame blood vessels, increase the risk of stroke or, more rarely, cause inflammation of the brain itself.
This has led researchers to ask an important question:
If shingles can affect the brain, could preventing shingles also help protect the brain?
What have the studies found?
Several large studies involving older adults have reported that people who received a shingles vaccine were less likely to be diagnosed with dementia during the following years than people who were not vaccinated.
Some media reports have highlighted a 20% reduction in dementia risk.
That figure is accurate, but it needs context.
It does not mean that one in five people will avoid dementia because they have been vaccinated. Nor does it mean that the vaccine has been proven to prevent Alzheimer’s disease.
Rather, researchers found that, when large groups of older people were followed over several years, those who had received the vaccine were somewhat less likely to develop dementia than those who had not.
That is an encouraging finding, but it is not yet the final answer.
Does it prevent Alzheimer’s disease?
At present, we simply do not know.
Most studies have examined all-cause dementia, rather than specific conditions such as Alzheimer’s disease, vascular dementia or Lewy body dementia. Researchers are still trying to determine exactly which types of dementia, if any, are most affected.
Equally important, scientists are continuing to investigate why this association exists. It may be that preventing shingles reduces inflammation or protects blood vessels that supply the brain. It is also possible that the vaccine has broader effects on the immune system. These questions are still being actively studied.
The bigger message
Perhaps the most important lesson from this research has little to do with the vaccine itself.
Increasingly, scientists recognise that many aspects of our general health influence brain health. Blood pressure, diabetes, physical activity, sleep, hearing, social engagement, smoking, infections and inflammation all appear to play a role in our long-term risk of dementia.
No single factor determines brain health. Instead, it reflects the combined influence of many small factors throughout life.
If future research confirms that shingles vaccination reduces dementia risk, it is likely to become another piece of that much larger puzzle—not a magic solution, but one more way in which protecting our overall health may also help protect our brains.
Should you consider the vaccine?
The shingles vaccine is recommended because it is highly effective at preventing shingles and its complications. That alone is an important benefit, particularly for older adults.
The possibility that it may also help reduce the risk of dementia is an exciting area of research, but it should be regarded as a potential additional benefit rather than the primary reason for vaccination.
The shingles vaccine is available in South Africa by prescription. It requires two injections given about six months apart and is relatively expensive. If you are interested in vaccination, speak to your doctor or pharmacist about whether it is appropriate for you, what it costs and the recommended vaccination schedule.
As scientists continue to learn more, one message is becoming increasingly clear: looking after the brain means looking after the whole person.
The emerging research on shingles reminds us that dementia is not simply an inevitable consequence of ageing. While no single intervention can eliminate the risk, many small steps—maintaining good cardiovascular health, exercising regularly, sleeping well, staying socially and mentally active, managing chronic medical conditions, preventing infections where possible and keeping vaccinations up to date—may together make a meaningful difference.
Although the research on shingles vaccination is exciting, it is important to remember that many of the most effective ways of protecting brain health remain controlling blood pressure, exercising regularly, sleeping well, avoiding smoking, treating diabetes and remaining socially and mentally active. These continue to form the foundation of dementia prevention. An expanding body of scientific research supports this encouraging message.
Selected References & Further Reading
Shingles Vaccination and Dementia Risk
Eyting, M., Xie, M., Michalik, F., Heß, S., Chung, S., & Geldsetzer, P. (2025). A natural experiment on the effect of herpes zoster vaccination on dementia. Nature, 641, 438–446.
Rayens, E., Sy, L. S., Tseng, H. F., Qian, L., Bruxvoort, K. J., & Ackerson, B. K. (2026). Recombinant zoster vaccine is associated with a reduced risk of dementia. Nature Communications, 17, Article 1457.
Taquet, M., Dercon, Q., Todd, J. A., & Harrison, P. J. (2024). The recombinant shingles vaccine is associated with lower risk of dementia. Nature Medicine, 30, 2777–2781.
Viral Infections and Brain Health
Itzhaki, R. F. (2018). Corroboration of a major role for herpes simplex virus type 1 in Alzheimer’s disease. Frontiers in Aging Neuroscience, 10, Article 324.
Frontiers in Aging Neuroscience
Levine, K. S., Leonard, H. L., Blauwendraat, C., Iwaki, H., Johnson, N., Bandres-Ciga, S., Ferrucci, L., Faghri, F., & Singleton, A. B. (2023). Virus exposure and neurodegenerative disease risk across national biobanks. Neuron, 111(7), 1086–1093.e2.
Dementia Prevention and Risk Reduction
Livingston, G., Huntley, J., Liu, K. Y., Costafreda, S. G., Selbæk, G., Alladi, S., Ames, D., Banerjee, S., Burns, A., Brayne, C., Fox, N. C., Ferri, C. P., Gitlin, L. N., Howard, R., Kales, H. C., Kivimäki, M., Larson, E. B., Nakasujja, N., Rockwood, K., … Mukadam, N. (2024). Dementia prevention, intervention, and care: 2024 report of the Lancet Standing Commission. The Lancet, 404(10452), 572–628.
World Health Organization. (2019). Risk reduction of cognitive decline and dementia: WHO guidelines. World Health Organization.
Information About Shingles and Vaccination
Centers for Disease Control and Prevention. (2024). About shingles (herpes zoster).
Centers for Disease Control and Prevention
Centers for Disease Control and Prevention. (2024). Shingles vaccination.
Centers for Disease Control and Prevention
About this Series
The Brain Health Education Series provides evidence-based information about brain health, dementia and neurological disorders. Our aim is to explain new research in clear language, distinguish established evidence from emerging findings, and help readers make informed decisions about their brain health.
