Science

Protect your brain: shingles vaccine may reduce dementia risk, study finds

A Stanford University-led study, whose results have been published in Nature, has found evidence that the shingles vaccine leads to a reduced risk of dementia.

Annie Rice

William Allen

British journalist and translator who joined Diario AS in 2013. Focuses on soccer – chiefly the Premier League, LaLiga, the Champions League, the Liga MX and MLS. On occasion, also covers American sports, general news and entertainment. Fascinated by the language of sport – particularly the under-appreciated art of translating cliché-speak.

Update: Apr 18th, 2025 05:07 EDT

New research suggests the shingles vaccine could help to reduce people’s risk of suffering from dementia.

Published in the journal Nature this month, a study led by Stanford University scientists focused on a group of older adults in the U.K. - and found that those who had received the shingles vaccine were 20% less likely to develop dementia than those who were not vaccinated.

What is shingles?

Shingles, also known as herpes zoster, is described by the World Health Organization (WHO) as a “viral infection that causes a painful rash”.

The illness is brought about by the varicella-zoster virus (VZV). According to the WHO, shingles occurs when VZV, which causes chickenpox, reactivates in the body of a person who has previously had chickenpox.

Shingles, which mostly occurs in adults over 50, affects around one million people each year in the U.S., per the country’s Centers for Disease Control and Prevention (CDC).

What is dementia?

Dementia, defined by the CDC as a “decline in mental ability” that impairs “memory, thinking, and behavior”, affects more than six million Americans, according to the U.S. Department of Health and Human Services (HHS).

The HHS notes that dementia, which chiefly develops in older people, accounts for more than 100,000 deaths each year in the U.S.

So how did the shingles vaccine study work?

Led by Stanford’s Markus Eyting, a postdoctoral fellow in primary care and population health, a team of researchers took advantage of what they describe as a “natural experiment” that began in Wales in 2013.

That year, a shingles vaccination program was rolled out for senior citizens, with anyone who was 79 on September 1 made eligible for the shot for a 12-month period. If you had turned 80 by that date, you could not have the vaccine; if you were 78, you would become eligible the following year.

This allowed the researchers to compare individuals with similar health traits who were very close in age, but were differentiated by their eligibility or ineligibility for the vaccine. In all, the scientists looked at the health records of 280,000 people in Wales.

“They focused their analysis on those closest to either side of the eligibility threshold - comparing people who turned 80 in the week before with those who turned 80 in the week after,” Stanford science writer Nina Bai says in a press release.

“This huge protective signal was there”

Pascal Geldsetzer, a Stanford assistant professor of medicine who is one of the paper’s co-authors, notes: “What makes the study so powerful is that it’s essentially like a randomized trial with a control group - those a little bit too old to be eligible for the vaccine - and an intervention group - those just young enough to be eligible.”

The results, which tallied dementia diagnoses during the period up to 2020, were “really striking”, says Geldsetzer. “This huge protective signal was there, any which way you looked at the data.”

“Pretty strong effect”

An apparent 20% protection against dementia represents “a pretty strong effect”, agrees Allison Aiello, a professor of epidemiology at New York’s Columbia University, in an interview with NBC News.

The study’s finding “does fit with other research suggesting that herpes viruses might have an influence on dementia”, she adds.