New research found that older adults who received the shingles vaccine currently used in the United States were less likely to be diagnosed with dementia within four years.
A vaccine designed to prevent the painful viral infection known as shingles may also help protect the aging brain. A new study found that older adults who received the shingles vaccine after a stay in a skilled nursing facility were 24% less likely to be diagnosed with dementia over the following four years than similar adults who were not vaccinated.
The analysis drew on Medicare data and health records from more than 500,000 adults aged 66 and older who had been admitted to skilled nursing facilities for either short-term or long-term care. Researchers compared people who received at least one dose of the recombinant shingles vaccine, Shingrix, with those who remained unvaccinated.
“A lot of previous studies with similar results focused on an older vaccine,” said study author Kaley Hayes, an assistant professor at Brown University’s School of Public Health. “This study looks at the newest vaccine only in an older, vulnerable adult population who were not up to date with shingles vaccination and are at a very clear clinical point in care: entering a skilled nursing facility.”
The results add to earlier research on a previous shingles vaccine that also found a link between shingles vaccination and lower dementia risk.
“It fits into this large puzzle that’s just starting to come together that the vaccines are effective at preventing shingles and also appear to have neuroprotective benefits as well,” said Hayes, who is also the associate director of pharmacoepidemiology for Brown’s Center for Gerontology and Healthcare Research.
Hayes led the study, which was published in Annals of Internal Medicine, with colleagues from Brown, the University of Delaware, the Providence Veterans Affairs Medical Center, and other institutions.
A trial-like records test
For the analysis, Hayes and colleagues used target trial emulation, a research approach that attempts to recreate key features of a randomized clinical trial when an actual trial would be difficult or impractical. The dataset included Medicare claims and electronic health records from patients admitted to more than 5,500 skilled nursing facilities across the United States between 2017 and 2022. Of the 509,926 participants, 8,843 received the vaccine.
Participants had to be eligible for shingles vaccination and could not have a previous dementia diagnosis. After four years of follow-up, adults who received at least one of the two recommended Shingrix doses had a markedly lower chance of being diagnosed with dementia than those who were not vaccinated. The data showed that 18.8% of vaccinated adults developed dementia within four years, compared with 24.6% of unvaccinated adults.
“This translates to about one in 17 dementia cases potentially being prevented,” Hayes said.
The main limitation is that the study cannot prove that the vaccine itself caused the lower dementia rate. People who received the vaccine were somewhat younger and healthier than those who did not, and those differences may have influenced dementia risk. Hayes and colleagues adjusted for those factors and found that they did not fully explain the association. Clinical trials and additional research will be needed to determine whether Shingrix directly lowers dementia risk.
A possible brain benefit
The findings suggest that a widely available vaccine might have benefits beyond preventing shingles, potentially offering protection for both physical and cognitive health.
“Our cognition is so tied to our overall health and what happens to us physically,” Hayes said. “It’s really amazing to see that something that’s supposed to prevent a physical ailment can also help keep our brain healthy, too.”
Reference: “Dementia Risk After Recombinant Herpes Zoster Vaccination in Older Adults With a Recent Skilled-Nursing Facility Stay” by Kaleen N. Hayes, Daniel A. Harris, Kevin W. McConeghy, Lexie R. Grove, Richa Joshi, Lisa Han, H. Edward Davidson, Preeti Chachlani, Thomas A. Bayer, Mriganka Singh, Yasin Abul, Frank DeVone and Stefan Gravenstein, 15 June 2026, Annals of Internal Medicine.
DOI: 10.7326/ANNALS-25-04689
Disclosure: In the study, the authors acknowledged funding from GlaxoSmithKline, which makes the shingles vaccine Shingrix, noting that the company had no control over the study design, analysis, or decision to publish the results.
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