Irish doctors are hopeful that the discovery of a link between the flu vaccine and a 40% reduced risk of Alzheimer’s disease will encourage more patients to get the jab before the winter flu season takes hold, according to a leading medical professor.
Clinical associate professor of medical gerontology at Trinity College Dublin Dr Sean Kennelly said the “evidence is so strong” that the vaccine is associated with reducing the risk of developing dementia.
However, he added that so far, it is “a message that’s just not out there”.
A recent study from the University of Texas Health Science Center at Houston analysed data from two million patients.
Dr Paul E Schulz, neurologist with McGovern Medical School at UTHealth Houston, is one of the lead authors of the study.
Speaking to RTÉ News, Dr Schulz said they were “shocked” that it was 40%.
“It was like a complete home run,” he said.
On Thursday, Dr Schulz and the other authors of this report will present these findings to a US government department in Washington DC – a move that could see this evidence inform health policy there.
Meanwhile, the HSE has said that the National Immunisation Advisory Committee (NIAC) is undertaking “on-going reviews of their information based on available clinical information”.
A spokesperson for NIAC said that it could not comment “in advance of any potential advice”.
The HSE said that it is now “finalising this season’s campaign and will be aiming to give everyone who can get the free flu vaccine the information they need to make an informed decision”.
Dr Kennelly, who is also a consultant physician in geriatric and stroke medicine in Tallaght University Hospital, said: “Over the age of 65, everybody should be getting the flu vaccine every single year and the benefits go beyond just reducing your risk of respiratory illness.”
“The benefit is very clearly associated with reducing your risk of developing dementia and, in particular, Alzheimer’s disease.
“This was a really strong study that kind of rubber stamped these signals that we’d seen in multiple smaller studies.”
He added that it is “so important and the evidence is so strong and it’s a message that’s just not out there”.
Dr Schulz explained that the research was based on a very large sample.
“90,000 people were diagnosed with Alzheimer’s in the unvaccinated group and only 50,000 in the vaccinated group over eight years,” he said.
“There’s almost 900,000 people in each group, so it’s a really large group of people.”
Dr Schulz said there has been considerable reaction to the findings.
“It’s something people can understand, say your parents might ask ‘should I get the flu vaccine or not?’ and of course they’re not thinking about Alzheimer’s, because none of us thinks that we’re going to get something bad like that.
“This is something people could understand – get the flu vaccine, it helps. So, there’s a lot of lay people who have been very interested in it.”
The US government has taken a keen interest in the research.
“Out of the blue, about three or four weeks ago, I got an email from someone in the US government. There’s a whole department called the HHS (Health and Human Services).
“HHS is the umbrella, it’s a cabinet level organisation, and it runs Medicare, so it runs insurance for Americans over 65 and some people with disabilities under 65. It also runs the FDA, which is in charge of approving drugs for use, or not approving them.
“They called some other authors and I on our paper and said ‘would you come and testify before our committee?'”
He will travel to Washington DC and present these findings on Thursday.
Meanwhile, Prof Kennelly outlined the benefits that have been associated with the flu vaccine.
“Vaccination is associated with reducing the risk that our inflammatory system, our immune system, has to respond to these outside triggers, so in the case of Alzheimer’s disease, we know there are proteins that build up in the brain,” Prof Kennelly said.
“When the brain detects those proteins, it charges up the immune system to counteract them, and we believe that vaccination and subsequent years’ vaccination probably dampens down that immune response, which can actually damage the brain almost as much if not more than the proteins themselves and trigger it.”
He also said that it is not just dementia, but that the influenza vaccination is associated with a significantly reduced risk of developing a stroke and of developing a heart attack.
“Not only is there a benefit that we would notice if you have one dose, but the more years you get your flu vaccine, the greater the impact seems to be and we’ve known this for quite a while,” he added.
“For stroke and heart disease, we’ve known this certainly since the early 2000s. For dementia, the information has been coming through from multiple sources over the last five years, so it’s more new and novel.”
64,000 people living with dementia in Ireland
September is World Alzheimer’s Month.
Cormac Cahill, head of advocacy, research and public affairs with The Alzheimer Society of Ireland has also welcomed the findings of this study.
It’s great to see more research being done and the more research that’s being done, the better, quite frankly, because all of this leads to a greater public awareness of dementia,” he said.
“There’s an estimated 64,000 people living with dementia in Ireland at the moment, but we feel that figure is actually much bigger, because of the stigma that’s still unfortunately attached to dementia, we feel it’s under-reported.
“Some people don’t want to come forward and admit that they have signs or early symptoms of dementia.”
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