Study pinpoints widely available vaccine that reduces dementia risk by at least 20% – have you had it?

A shingles vaccine, already offered on the NHS, could dramatically reduce the risk of dementia, a major new study has found.

The research has shown that older adults given the jab are 20 per cent less likely to develop the condition compared to those who aren’t vaccinated. 

Shingles, a viral infection that produces a painful rash, is caused by the same virus that causes chicken pox—varicella-zoster.

Since 2013, everyone aged 70 to 79 in England is eligible for two shots to help reduce the risk of the condition. 

The new findings add to mounting evidence it also has an unexpected benefit, in preventing dementia—although doctors are still unsure why this happens.

In the study, scientists from Stanford University analysed more than 280,000 older adults aged—between 71 to 88 years old—in Wales.

They compared records of people who received the vaccine and those aged 80 and over that at the time of roll out in 2013 who were not eligible under the NHS scheme—some just a week apart in age.

By 2020, one in eight older adults, who were by then 86 and 87, had been diagnosed with dementia.

But those who received the shingles vaccine were a fifth less likely to have developed condition than the unvaccinated, the study published in the journal Nature reveals.

‘It was a really striking finding,’ said Dr Pascal Geldsetze, who led the study. ‘This huge protective signal was there, any which way you looked at the data.

‘What makes the study so powerful is that it’s essentially like a randomised trial with a control group—those a little bit too old to be eligible for the vaccine, and an intervention group, those just young enough to be eligible.’

Researchers found that the impact of the vaccine on developing dementia was greater in women, which may be due to the fact that women naturally have a stronger immune system reaction to vaccines. 

Experts have hailed the study as an important step forward.

Dr Henry Brodaty, Professor of Ageing and Mental Health at the University of New South Wales, said: ‘There has been evidence for some time that older people who receive their vaccinations in general are less likely to develop dementia. 

‘This is the best evidence yet to show this.’

Some warn though that there are still questions left unanswered by the research.

Around 900,000 Britons are currently thought to have the memory-robbing disorder. But University College London scientists estimate this will rise to 1.7million within two decades

Professor Anthony Hannan, a neuroscientist at the Florey Institute, in Melbourne, Australia said: ‘A key question, not answered by this new study, is how the shingles vaccine may have helped protect against dementia.

‘The next step is to work out exactly how this vaccine exerts its protective effects against dementia and to use that information to develop new ways to prevent and treat dementia.’

The Stanford research team behind the study has replicated the Wales findings in health records from other countries, including England, Australia, New Zealand and Canada, that had similar rollouts of the vaccine.

They are also investigating whether a newer version of the vaccine—which is more effective at preventing shingles—has a greater impact on the risk of developing dementia.

There are currently around 982,000 people with dementia in the UK. This number is expected to rise to 1.4 million by 2040.

Alzheimer’s affects around six in 10 people with dementia.

Memory problems, thinking and reasoning difficulties and language problems are common early symptoms of the condition, which then worsen over time.