Herpes Zoster Vaccination and Incident Dementia in Canada

Dr. Margarita Fedorova talks with Dr. Pascal Geldsetzer about how the herpes zoster vaccination may have neuroprotective effects, potentially delaying or preventing dementia.

Read the related article in The Lancet Neurology.

Disclosures can be found at Neurology.org.

Podcast Transcript:

Dr. José Merino:

This is José Merino, editor-in-chief of the Neurology Family of Journals. The Neurology Podcast provides practical information to neurologists and other clinicians to help them provide better care for their patients. Thanks for listening and have a great week.

Dr. Margarita Fedorova:

Hi, this is Margarita Fedorova and I'm a neurology resident at the Cleveland Clinic. Today, we're exploring a study that speaks to an idea that's been building for a few years now, that vaccination itself might be neuroprotective.

I'm here with Pascal Geldsetzer, a physician and epidemiologist at Stanford University. Pascal is the author on a paper published in the February 2026 issue of Lancet Neurology titled "Herpes Zoster Vaccination and Incident Dementia in Canada: An Analysis of Natural Experiments." What makes the study different is how they got at the question. When Ontario started publicly funding the shingles vaccine, eligibility came down almost entirely to date of birth. People born a few weeks on one side of a cutoff could get the vaccine for free, and people born a few weeks on the other side could not.

That left Pascal and his colleagues with two groups of older adults who should be alike in essentially every way, except their access to the vaccine. And they asked whether those groups went on to develop dementia in different rates. We wanted to bring Pascal to the podcast because this is a question our patients are already asking us in clinic, and because vaccination is one of the few things we can offer an older adult that might actually protect the brain. Pascal, welcome to the podcast.

Dr. Pascal Geldsetzer:

Thank you very much for having me.