New research adds to a growing body of evidence suggesting that shingles vaccination may reduce the risk for dementia.

Published in Annals of Internal Medicine, the research found Medicare beneficiaries who received the recombinant zoster vaccine had a 24% lower relative risk for dementia than their unvaccinated peers. While experts remain divided on whether the brain-protecting benefit stems from a biological reaction or simply from preventing virus-induced neuroinflammation, some frontline clinicians are already leveraging the findings as a selling point to counter vaccine hesitancy.

“I’ve added it to my standard pitch as to why they should get the vaccine: I start with, ‘Shingles is probably the most painful rash imaginable, and you’re lucky if it lasts just a few weeks and goes away.’ And then I add that there is some evidence that it may help protect your brain,” said Barak Gaster, MD, director of the Cognition in Primary Care Program at the University of Washington in Seattle, who was not associated with the new research.

The observational study included claims and electronic health record data from over 500,000 Medicare beneficiaries (mean age, 79 years; 64% female; 84% White) admitted to skilled nursing facilities between 2017 and 2022.

Receipt of at least one dose of the vaccine within 12 months of admission was associated with a 24% lower relative risk for dementia compared with no vaccination (0.76; 95% CI, 0.69-0.84). After 4 years of follow-up, the risk for dementia was 18.8% among vaccine recipients compared with 24.6% among nonrecipients.

“We don’t know with certainty why the risk of dementia is lower with shingles vaccination, but have a lot of ideas,” said Kaleen Hayes, PharmD, PhD, associate director of pharmacoepidemiology at the Brown University School of Public Health in Providence, Rhode Island, who led the study. “Activating the immune system against a particular future infection with vaccination may also help to reduce an unknown pathway of inflammation that increases dementia risk.”

Contracting shingles could potentially accelerate dementia through two pathways: by provoking neuroinflammation and increasing a patient’s vulnerability to stroke.

“The takeaway from this research is ‘stay tuned,’” said David Reuben, MD, professor of geriatrics at the David Geffen School of Medicine at UCLA in Los Angeles, who was not involved with the study. “I tell patients, ‘yes, there is some evidence supporting this, but it’s very early.’ I wouldn’t change my practice over this, but it’s interesting.”

Reuben and Gaster reported having no disclosures. GSK funded the study.

Brittany Vargas is a journalist covering medicine, mental health, and wellness.