Shingles Vaccine Reduces Risk of Dementia
In Wales, the shingles vaccinated reduced risk of dementia by 20% and helped those with dementia
Key points:
- The shingles vaccine lessens dementia risk
- For those with dementia, the shingles vaccine slows disease progression
Stanford Study on Patient Records from Wales
Using data from the electronic health records from people in Wales, scientists at Stanford University concluded that the original shingles (herpes zoster) vaccine reduced the risk of dementia.
In addition, this April 2025 report showed that the version of the shingles vaccine made from the inactivated live virus slowed the progression of dementia in those who already had it.
This study was especially reliable because the data set approximated the standards for randomized control trials. The vaccine rollout created random groups of those who received the vaccine and those who were ineligible. Often, there is a wide disparity between education levels, lifestyle, or exposure to other diseases between those who chose vaccines and those who don’t, leaving the possibility that other factors affecting outcomes. Not so in this case.
In 2013, the government of Wales rationed the shingles vaccine based solely on birthdays. Other than being born a short time apart, the groups of vaccine recipients and non-recipients had no distinguishing characteristics.
About seven years after inoculation, those fully vaccinated were 20% less likely to have been diagnosed with dementia.
Remarkably, those already diagnosed with dementia when they got the vaccine had experienced slower progression of dementia.
“It was a really striking finding,” said Dr. Pascal Geldsetzer, one of the study’s main authors. “This huge protective signal was there, any which way you looked at the data.”
Scientists noted that vaccinated women benefitted even more than men. This is thought to be due to immune system differences. Also, more females than males get shingles. Often, women experience worse cases of shingles than men.
Similar Results on Australians
Dr. Geldsetzer and his colleagues further examined data on vaccine recipients in Australia and again found that this older version of the shingles vaccine prevented dementia. The shingles vaccine slowed the progress of dementia and reduced death from dementia. Patients suffering from mild cognitive impairment also had slower progression of cognitive decline. This 2025 study concluded that the shingles (herpes zoster) vaccines positively impacted the entire course of dementia.
The individuals in these studies had been given the older version of the shingles vaccine, the Varicella Vaccine Injection. First developed in Japan, it was made from the conventional method, using an inactivated live virus. Vaccines made this way tend to lose effectiveness over time. In 2020, that vaccine was replaced by the recombinant version Shingrix. Shingrix is made from proteins in a lab. See related article Current Shingles Vaccine Protects Against Dementia.
The shingles vaccine is recommended for adults age 50 and over and young people who are immunocompromised or immunosuppressed.
Dementia is an umbrella term for Alzheimer’s and similar disease of cognitive decline.
