New shingles vaccine found to reduce risk of dementia
New evidence indicates that a new shingles vaccine is more protective against dementia compared to the previous shingles vaccine, which was also reported to reduce dementia rates.
It is also more protective than vaccines against other infections.
A study of more than 200,000 people by researchers at the University of Oxford found at least a 17% reduction in dementia diagnoses in the six years after new recombinant shingles vaccination ‘Shingrix’, equating to 164 or more additional days lived without dementia.
The benefit was seen in both sexes but was greater in women.
The study was funded by the National Institute for Health and Care Research (NIHR) Oxford Health Biomedical Research Centre (OH BRC).
These findings suggest that the recombinant shingles vaccine may have additional value in terms of protection against dementia. The researchers have cautioned that further research is needed to confirm this, and to identify how and why the vaccine has this effect.
Shingles is caused by the Herpes zoster virus that can flare up in people who previously had chicken pox.
A previous study at UTHealth Houston in the US found that vaccines for tetanus, diphtheria, shingles, and pneumococcus are linked to a significant reduced risk of Alzheimer’s disease (AD).
Significant implications for older adults
In the new study, researchers used the USA TriNetX electronic health records network, where there was a switchover between Zostavax (the previous shingles vaccine) and Shingrix in October 2017.
Shingrix was also compared to people who had received vaccines against other infections (flu and tetanus, diphtheria, and pertussis) and was found to be associated with a 23-27% lower risk.
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, added: “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.”
Diana Spencer, Senior Digital Content Editor, DDW