Routine vaccines may protect against dementia, research finds

Routine vaccines for adults may reduce dementia risk, a review of more than 100 million people suggests.

The research found both flu and shingles vaccines were associated with a lower risk in adults aged 50 and over.

The shingles (herpes zoster) jab was linked to a 24 per cent lower risk of any dementia and a 47 per cent lower risk of Alzheimer’s disease.

A joint Italian-Canadian neuroscience review points to a pattern that public health experts say is hard to ignore, suggesting vaccines against common infections may offer long-term protection against the UK’s leading cause of death.

With an ageing population, about two million people are projected to be living with dementia in the UK by 2050.

Prof Sir Andrew Pollard is director of the Oxford Vaccine Group and former chair of the Joint Committee on Vaccination and Immunisation.

He said: “Vaccines for pneumonia, shingles, and influenza in older adults have been shown to reduce the risk of serious infections and hospitalisation caused by these diseases.

“But studies in the past few years have raised the intriguing possibility that vaccination could also provide a welcome reduction in the risk of dementia, a disease which places a huge burden on society and the NHS.”

A separate large-scale randomised trial in Wales compared shingles vaccines Zostavax and Shingrix to address the “healthy user effect”, where people who get vaccinated tend to be more health-conscious. As both groups were vaccinated, this helped control for that bias.

The results showed those receiving the newer Shingrix vaccine had a substantially lower risk of developing dementia over subsequent years.

Dr Maxime Taquet, clinical lecturer in psychiatry at Oxford, who led that study, said: “The size and nature of this study makes these findings convincing, and should motivate further research.”