New vaccine shows potential to reduce dementia risk

A new vaccine used to fight a common infection in older people may reduce your risk of developing dementia, according to a recent UK study.

Researchers at the University of Oxford analysed the health records of 200,000 older adults from the United States and found that participants who were vaccinated with Shringrix, a newer shingles vaccine, were less likely to develop dementia than those vaccinated with the older Zostavax jab.

Shingles is a painful condition afflicting many elderly people that is caused by the Herpes zoster virus and can flare up in people who previously had chicken pox. The risk of developing shingles increases as we get older. This is because as we age, particularly after 50, our immune system naturally declines. Those who have a weakened immune system are also at risk of catching the debilitating virus.

The study found that people who received the Shingrix vaccine had a 17 per cent reduced risk of being diagnosed with dementia compared with people who received the Zostavax vaccine.

Shingrix was also associated with delayed onset of dementia for participants who eventually developed the disease. The researchers said this amounted to 164 days dementia free or a five-month delay before getting the disease.

Oxford University researcher Dr Maxime Taquet said the findings support the hypothesis that vaccination against shingles might prevent dementia.

“The size and nature of this study makes these findings convincing, and should motivate further research,” she said.

“If validated in clinical trials, these findings could have significant implications for older adults, health services, and public health.”

While the researchers were excited by their findings, they emphasised more research was needed to understand the connection between Shingles and Dementia.

Professor of Medicine at Oxford University, John Todd said researchers still did not know how the vaccine produced 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,” he said.

“Alternatively, the vaccine also contains chemicals which might have separate beneficial effects on brain health.”

The study’s supervisor, Professor Paul Harrison said the findings were “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,” Harrison said.

Closer to home, Shingrix replaced Zoxtava in the Australian National Immunisation Program in November 2023.

The Federal Government also made the vaccine free for those at the highest risk of complications from shingles such as all adults aged 65 and over, First Nations people aged 50 and older, and younger adults with certain medical conditions that affect their immune systems.

The vaccine, which typically costs up to $560 per person, was expected to benefit nearly 5 million Australians who are at risk of severe shingles-related complications.

When announcing the program, Minister for Health and Aged Care Mark Butler said “Older Australians will now have free access to the best protection against shingles through one of the most comprehensive and widely available vaccination programs in the world.”

“Without vaccination, almost one in three Australians will get shingles in their lifetime,” Butler said at the time.

“This investment will ensure nearly five million Australians can get free protection from shingles and the very painful nerve damage that it causes.

“Shingles can be severe, so it’s really important that eligible people talk to their GP or pharmacist about getting the shingles vaccine.”