Could the shingles vaccine reduce your risk of developing dementia?

A recent study led by Stanford Medicine has found evidence suggesting that the shingles vaccine may reduce the risk of developing dementia.

The research, published on April 2 in Nature, analysed the health records of older adults in Wales and discovered that those who received the shingles vaccine were 20 per cent less likely to develop dementia over the next seven years compared to those who did not receive the vaccine.

Shingles is a viral infection that is caused by the reactivation of the same virus that causes chickenpox (also known as the varicella zoster virus), resulting in a painful, blistering skin rash. It’s a disease that can affect anyone, at any age who has had chickenpox, but it is most common in people 50 years of age and older.

The study’s findings support an emerging theory that certain viral infections affecting the nervous system might contribute to the development of dementia.

To test the shingles vaccine’s effectiveness in reducing dementia risk, researchers took advantage of a unique “natural experiment” in Wales that helped avoid bias common in similar studies. In 2013, the Welsh government started offering the shingles vaccine to people aged 79, with eligibility depending on the person’s exact birthdate.

This system meant that people just shy of turning 80 could receive the vaccine, while those just a few days older were not eligible. This created a perfect opportunity to compare the health outcomes of two groups who were nearly identical in age but had different access to the vaccine.

By studying over 280,000 older adults between the ages of 71 and 88, the researchers focused on those close to the eligibility threshold. They found that those who were eligible for the vaccine had a 20 per cent lower risk of developing dementia compared to those who were ineligible. Additionally, the vaccine reduced the occurrence of shingles by 37 per cent, which aligned with previous clinical trial results.

“It was a really striking finding,” Pascal Geldsetzer, MD, PhD, assistant professor of medicine and senior author of the new study said.

“This huge protective signal was there, any which way you looked at the data.”

Interestingly, the protective effect of the vaccine against dementia was more pronounced in women than in men. This could be due to differences in immune responses between the sexes or the fact that shingles is more common in women.

Researchers have since replicated these findings in other countries with similar vaccine rollouts, including England, Australia, New Zealand, and Canada, showing consistent results.

Geldsetzer hopes the study’s findings will inspire more funding for further research into this promising connection between the shingles vaccine and dementia prevention.

This research is especially timely, with Dementia Australia reporting that the number of people living with dementia is projected to nearly double in the next 30 years—from 433,300 to 812,500—unless urgent action is taken. The number of younger people diagnosed with dementia is also expected to rise significantly, from 12,000 to 41,000.

IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.