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Could the shingles vaccine lower your risk of dementia?

<div class="theconversation-article-body"><em><a href="https://theconversation.com/profiles/ibrahim-javed-1552271">Ibrahim Javed</a>, <a href="https://theconversation.com/institutions/university-of-south-australia-1180">University of South Australia</a></em></p> <p>A <a href="https://www.nature.com/articles/s41591-024-03201-5">recent study</a> has suggested Shingrix, a relatively new vaccine given to protect older adults against shingles, may delay the onset of dementia.</p> <p>This might seem like a bizarre link, but actually, <a href="https://pubmed.ncbi.nlm.nih.gov/34697158/">research</a> has previously shown an older version of the shingles vaccine, Zostavax, reduced the risk of dementia.</p> <p>In this new study, published last week in the journal Nature Medicine, researchers from the United Kingdom found Shingrix delayed dementia onset by 17% compared with Zostavax.</p> <p>So how did the researchers work this out, and how could a shingles vaccine affect dementia risk?</p> <h2>From Zostavax to Shingrix</h2> <p>Shingles is a viral infection caused by the varicella-zoster virus. It causes <a href="https://www.healthdirect.gov.au/shingles">painful rashes</a>, and affects older people in particular.</p> <p>Previously, Zostavax was used to vaccinate against shingles. It was administered as a single shot and provided good protection for about <a href="https://immunisationhandbook.health.gov.au/contents/vaccine-preventable-diseases/zoster-herpes-zoster">five years</a>.</p> <p>Shingrix has been developed based on a newer vaccine technology, and is thought to offer stronger and longer-lasting protection. Given in two doses, it’s now the preferred option for shingles vaccination in Australia and elsewhere.</p> <p>In November 2023, Shingrix replaced Zostavax on the <a href="https://www.health.gov.au/news/national-immunisation-program-changes-to-shingles-vaccination-from-1-november-2023">National Immunisation Program</a>, making it available for free to those at highest risk of complications from shingles. This includes 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.</p> <h2>What the study found</h2> <p>Shingrix was approved by the US Food and Drugs Administration in <a href="https://www.drugs.com/history/shingrix.html">October 2017</a>. The researchers in the new study used the transition from Zostavax to Shingrix in the United States as an opportunity for research.</p> <p>They selected 103,837 people who received Zostavax (between October 2014 and September 2017) and compared them with 103,837 people who received Shingrix (between November 2017 and October 2020).</p> <p>By analysing data from electronic health records, they found people who received Shingrix had a 17% increase in “diagnosis-free time” during the follow-up period (up to six years after vaccination) compared with those who received Zostavax. This was equivalent to an average of 164 extra days without a dementia diagnosis.</p> <p>The researchers also compared the shingles vaccines to other vaccines: influenza, and a combined vaccine for tetanus, diphtheria and pertussis. Shingrix and Zostavax performed around 14–27% better in lowering the risk of a dementia diagnosis, with Shingrix associated with a greater improvement.</p> <p>The benefits of Shingrix in terms of dementia risk were significant for both sexes, but more pronounced for women. This is not entirely surprising, because we know women have <a href="https://www.alzheimers.org.uk/blog/why-dementia-different-women">a higher risk</a> of developing dementia due to interplay of biological factors. These include being more sensitive to certain genetic mutations associated with dementia and hormonal differences.</p> <h2>Why the link?</h2> <p>The idea that vaccination against viral infection can lower the risk of dementia has been around for more than two decades. Associations have been <a href="https://pubmed.ncbi.nlm.nih.gov/11762573/">observed</a> between vaccines, such as those for diphtheria, tetanus, polio and influenza, and subsequent dementia risk.</p> <p>Research has shown Zostavax vaccination can <a href="https://bmjopen.bmj.com/content/11/10/e045871">reduce the risk</a> of developing dementia by 20% compared with people who are unvaccinated.</p> <p>But it may not be that the vaccines themselves protect against dementia. Rather, it may be the resulting lack of viral infection creating this effect. Research indicates bacterial infections in the gut, as well as viral infections, are associated with a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10169152/">higher risk of dementia</a>.</p> <p>Notably, untreated infections with herpes simplex (herpes) virus – closely related to the varicella-zoster virus that causes shingles – can <a href="https://alz-journals.onlinelibrary.wiley.com/doi/10.1002/trc2.12119">significantly increase</a> the risk of developing dementia. Research has also shown shingles increases the risk of a later dementia diagnosis.</p> <p>The mechanism is not entirely clear. But there are two potential pathways which may help us understand why infections could increase the risk of dementia.</p> <p>First, certain molecules are produced when a baby is developing in the womb to help with the body’s development. These molecules have the potential to cause inflammation and accelerate ageing, so the production of these molecules is silenced around birth. However, viral infections such as shingles can <a href="https://doi.org/10.1016/j.virol.2018.07.011">reactivate</a> the production of these molecules in adult life which could <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8717685/#:%7E:text=The%20disease%20mechanisms%20of%20AD,may%20lead%20to%20new%20therapies.">hypothetically lead to dementia</a>.</p> <p>Second, in Alzheimer’s disease, a specific protein called Amyloid-β go rogue and kill brain cells. Certain proteins produced by viruses <a href="https://www.biorxiv.org/content/10.1101/2024.05.16.594465v1">such as COVID</a> and <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/advs.202001299">bad gut bacteria</a> have the potential to support Amyloid-β in its toxic form. In laboratory conditions, these proteins have been shown to <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1003537">accelerate the onset</a> of dementia.</p> <h2>What does this all mean?</h2> <p>With an ageing population, the burden of dementia is only likely to become greater in the years to come. There’s a lot more we have to learn about the causes of the disease and what we can potentially do to prevent and treat it.</p> <p>This new study has some limitations. For example, time without a diagnosis doesn’t necessarily mean time without disease. Some people may have underlying disease with delayed diagnosis.</p> <p>This research indicates Shingrix could have a silent benefit, but it’s too early to suggest we can use antiviral vaccines to prevent dementia.</p> <p>Overall, we need more research exploring in greater detail how infections are linked with dementia. This will help us understand the root causes of dementia and design potential therapies.<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img style="border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important;" src="https://counter.theconversation.com/content/235597/count.gif?distributor=republish-lightbox-basic" alt="The Conversation" width="1" height="1" /><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https://theconversation.com/republishing-guidelines --></p> <p><em><a href="https://theconversation.com/profiles/ibrahim-javed-1552271">Ibrahim Javed</a>, Enterprise and NHMRC Emerging Leadership Fellow, UniSA Clinical & Health Sciences, <a href="https://theconversation.com/institutions/university-of-south-australia-1180">University of South Australia</a></em></p> <p><em>Image credits: Shutterstock </em></p> <p><em>This article is republished from <a href="https://theconversation.com">The Conversation</a> under a Creative Commons license. Read the <a href="https://theconversation.com/could-the-shingles-vaccine-lower-your-risk-of-dementia-235597">original article</a>.</em></p> </div>

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Why you need the new shingles vaccination

<p><em><strong><img width="149" height="149" src="https://oversixtydev.blob.core.windows.net/media/24698/maureen-photo_152x152.jpg" alt="Maureen Photo" style="float: left;"/>Maureen Helen, from Perth, Western Australia, left paid employment the year she turned 65 and enrolled in a PhD Writing course to satisfy a childhood dream. She has published two memoirs.</strong></em></p> <p><span style="text-decoration: underline;"><strong><a href="http://www.seqirus.com.au/s1/cs/aucb/1196562673365/.../ProductDetail.htm" target="_blank">Zostavax vaccine</a></strong></span> is now available in Australia. This vaccine helps to prevent the viral illness known as shingles. From November 2016 it will be offered free to people between the ages of 70 and 79. Others can be vaccinated by their general practitioner at their own expense.</p> <p>I will be the first in the queue. I’ve had shingles. I don’t want to experience the illness again.</p> <p><strong>What are shingles?</strong></p> <p>According to <span style="text-decoration: underline;"><strong><a href="http://www.medicalnewstoday.com/articles/154912.php" target="_blank">Medical News Today</a></strong></span>, “Shingles is an infection of a nerve and the surrounding skin surface that is supplied by the nerve, caused by the varicella-zoster virus. This is the same virus that causes chickenpox and anyone who has recovered from chickenpox, child or adult can get shingles.”</p> <p>Shingles causes pain and a rash along a band of skin supplied by an affected nerve. It can occur in a band around the abdomen or chest or elsewhere. The acute stage lasts for between two and four weeks. Full recovery takes longer. Ageing increases the risk of contracting the illness.</p> <p><strong>The effects of shingles</strong></p> <p>I discovered recently that shingles is no joke. I found the hard way that the disease is painful, debilitating and distressing. It affected my trigeminal nerve. The viral illness had sudden onset. Then a painful scabby rash spread across one side of my forehead, on to one eyelid and into my hair. The rash followed the route of the nerve from just above my ear. I became sensitive to light and unable to read. The horrid nerve pain (like electrical shocks) affected my sinuses, throat and ear on one side.</p> <p>And was it inconvenient?  Let me tell you how inconvenient it was. I anticipated April and May would be exciting, busy months for my family and me. </p> <p>Taking to my bed is not an option I would ever choose – but especially not at such a time. I fretted that I was missing out on things. Not being able to drive was a total bore. Needing to rest every afternoon as I recovered was tedious. Relying on so heavily on John seemed unfair to him, even though he was uncomplaining and comforting.</p> <p><strong>Some reasons why shingles was so annoying</strong></p> <p>My new great-grandchild was due any moment. I wanted to be there to congratulate my granddaughter and her husband.</p> <p>I wanted to begin to bond with this new baby as soon as he or she was born. Fortunately, he was in no hurry to be born.</p> <p>A timely recovery meant I could visit our newborn great-grandson</p> <p>Another granddaughter is being married next month. I wanted to be well and energetic for that. (And to be involved in preparations if I was invited.)</p> <p>I am committed to several ’causes’ and did not want to miss meetings.</p> <p>I also discovered, not for the first time, that general practitioners do not always take the illnesses of older people as seriously as they should. The ongoing disregard for the wisdom of seniors about their own health appals me. I’ve written about this before. It is one of the themes in my book, <em><strong><span style="text-decoration: underline;"><a href="http://stonespub.com.au/bookstore-stone-s-publishing.html#!/Elopement-a-Memoir-Maureen-Helen/p/60215458/category=0" target="_blank">Elopement: a Memoir</a></span></strong></em>.</p> <p>If someone who has contracted shingles is given anti-viral medication within 72 hours of onset, symptoms can be greatly relieved. The GP at the after-hours clinic was not convinced when I explained my symptoms. She declined to prescribe anti-viral medication. Instead, she diagnosed trigeminal neuralgia (which of course, is part of shingles). She prescribed an anti-convulsive medication used for epilepsy.</p> <p>By the following Monday when normal doctors were back at work, it was too late. The shingles had to run their course. I was very angry.</p> <p>Now I am recovering. I hope the scars on my face will fade. I am able to wash my hair again. I can read and drive short distances. I plan to be back in the pool soon, and walking longer distances every day.</p> <p><strong>Benefits and risks of Zostavax vaccine</strong></p> <p>Zostavax vaccine is a safe vaccine, which helps to prevent the occurrence of shingles. It is less effective the older a person is. If shingles do occur in spite of vaccination, the pain and rash are less severe. Post herpetic pain, which can be set off by trivial stimuli is less likely to occur.</p> <p>Many people query the use of vaccination. However, I am one of those people who has seen first-hand the effect of diphtheria, whooping cough, tuberculosis and polio. I nursed patients who died of those diseases. My children suffered through measles and chickenpox. They were unwell and missed school. Thanks to immunisation and vaccinations, these illnesses are no longer a “normal” part of childhood.</p> <p>If Zostavax vaccine can protect adults from unnecessary suffering, why not take advantage of it? Will you be going to get it? Let us know in the comments below.</p> <p><strong>Related links:</strong></p> <p><a href="http://www.oversixty.co.nz/health/mind/2016/07/alzheimers-vaccine-coming-in-3-years/"><em><span style="text-decoration: underline;"><strong>A vaccine for Alzheimer’s may be on the way</strong></span></em></a></p> <p><a href="/health/body/2016/06/bowel-cancer-screening-kit-saved-my-life/"><strong><em><span style="text-decoration: underline;">The bowel cancer screening kit saved my life</span></em></strong></a></p> <p><a href="/entertainment/books/2016/05/the-most-amazing-libraries-i-have-seen-around-the-world/"><strong><em><span style="text-decoration: underline;">The most amazing libraries I have seen around the world</span></em></strong></a></p>

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