Shingles vaccine reduces dementia risk, study suggests

A major new research study has delivered “convincing” findings that the recombinant shingles vaccine may also protect against dementia.

For the study, researchers at the University of Oxford used American electronic health records to analyse the risk of dementia between the old shingles vaccine (Zostavax) and the new vaccine (Shingrix), which the US switched to in October 2017.

Researchers found that the new vaccine was associated with a 17% lower risk of dementia than its predecessor.

Shingrix was also compared to vaccines for other infections such as flu and tetanus, diphtheria, and pertussis. Results suggest that the new shingles vaccine had a 23-27% reduced risk compared to those vaccines.

The researchers say this is the equivalent to 5-9 additional months without dementia and the benefits were present for men and women, but more pronounced in the latter.

“The size and nature of this study makes these findings convincing, and should motivate further research,” said study lead Dr Maxime Taquet, who is a clinical lecturer in Oxford University’s psychiatry department.

He added: “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.”

While these findings are promising, the research team emphasises that further investigations should be completed before Shingrix is considered as a viable option to prevent or delay a dementia diagnosis. Recent NHS England figures show that a record number of people are being diagnosed with dementia.

Dr Sheona Scales, research director at Alzheimer’s Research UK, says it is “critical” that further research is undertaken as the root cause of the effect remains unclear.

“It isn’t clear how the vaccine might be reducing risk, nor whether the vaccine causes a reduction in dementia risk directly or whether there’s another factor at play,” she said.

The study was funded by the National Institute for Health and Care Research Oxford Health Biomedical Research Centre. It has been published in the journal Nature Medicine and looked at a cohort of more than 200,000 people.

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