Published: 26 July 2024
A new study has found that the new shingles vaccine ‘Shingrix’ is more protective against dementia compared to the previous shingles vaccine.
The study was conducted by the University of Oxford and our NIHR Oxford Health Biomedical Research Centre. The researchers led a major study of more than 200,000 people. They found at least a 17% reduction in dementia diagnoses in the 6 years after the new shingles vaccination was administered. This equates to 164 or more additional days lived without dementia. The findings have been published in Nature Medicine.
Shingles is a painful and serious condition which commonly affects many elderly people. It is caused by the Herpes Zoster virus that can flare up in people who previously had chicken pox. A vaccine (Zostavax) against shingles was introduced in many countries in 2006. Since then there has been growing evidence that the jab could help protect against dementia. However, there was no conclusive proof.
In many countries, including the UK and US, Zostavax has now been replaced by a much more effective vaccine, called Shingrix. In the UK, Shingrix is being offered by the NHS to all elderly people and certain other groups.
In this study, researchers compared the health records of people in the US who had the older Zostavax jab with the newer Shingrix jab. This allowed the researchers to compare the risk of dementia in the 6 years following Shingrix to the risk in those who had received Zostavax. More than 100,000 people were in each group. Shingrix was also compared vaccines against other infections (flu and tetanus, diphtheria, and pertussis).
The findings:
- Shingrix was associated with 17% lower risk of dementia than Zostavax
- Shingrix was also associated with 23-27% lower risk of dementia than with the other vaccines compared
- This equals 5 to 9 more months lived without dementia
- The benefits of Shingrix were found in both sexes but were greater in women
These findings suggest that the new shingles vaccine may help to lower the risk of dementia. The researchers say further research is needed to confirm this, and to identify how and why the vaccine has this effect.
Dr Maxime Taquet, NIHR Academic Clinical Lecturer in the Department of Psychiatry at Oxford, who led the study said: “The size and nature of this study makes these findings convincing, and should motivate further research. They support the hypothesis that vaccination against shingles might prevent dementia. If validated in clinical trials, these findings could have significant implications for older adults, health services, and public health.”
John Todd, Professor of Precision Medicine at the University of Oxford’s Nuffield Department of Medicine, said: “A key question is, how does the vaccine produce its apparent benefit in protecting against dementia? One possibility is that infection with the Herpes zoster virus might increase the risk of dementia, and therefore by inhibiting the virus the vaccine could reduce this risk. Alternatively, the vaccine also contains chemicals which might have separate beneficial effects on brain health.”
Paul Harrison, Professor of Psychiatry, who supervised the study, said: “The findings are intriguing and encouraging. Anything that might reduce the risk of dementia is to be welcomed, given the large and increasing number of people affected by it.”