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I’m feeling run down. Why am I more likely to get sick? And how can I boost my immune system?

<div class="theconversation-article-body"> <p><em><a href="https://theconversation.com/profiles/sathana-dushyanthen-1169328">Sathana Dushyanthen</a>, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</a></em></p> <p>It has been a long winter, filled with many viruses and cost-of-living pressures, on top of the usual mix of work, study, life admin and caring responsibilities.</p> <p>Stress is an inevitable part of life. In short bursts, our stress response has evolved as a survival mechanism to help us be more alert in <a href="https://theconversation.com/no-you-cant-blame-all-your-health-issues-on-high-cortisol-heres-how-the-hormone-works-203162">fight or flight situations</a>.</p> <p>But when stress is chronic, it weakens the immune system and makes us more vulnerable to illnesses such as the <a href="https://www.healthline.com/health/can-stress-make-you-sick#:%7E:text=The%20common%20cold&amp;text=Inflammation%20has%20been%20linked%20to,to%20the%20cold%2Dcausing%20germs.">common cold</a>, <a href="https://journals.lww.com/psychosomaticmedicine/abstract/1999/03000/psychological_stress,_cytokine_production,_and.9.aspx">flu</a> and <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/smi.3017">COVID</a>.</p> <h2>Stress makes it harder to fight off viruses</h2> <p>When the immune system starts to break down, a virus that would normally have been under control starts to flourish.</p> <p>Once you begin to feel sick, the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4465119/">stress response</a> rises, making it harder for the immune system to fight off the disease. You may be sick more often and for longer periods of time, without enough immune cells primed and ready to <a href="https://link.springer.com/chapter/10.1007/978-3-030-16996-1_6">fight</a>.</p> <p>In the 1990s, American psychology professor Sheldon Cohen and his colleagues conducted a number of <a href="https://www.cmu.edu/common-cold-project/">studies</a> where healthy people were exposed to an upper respiratory infection, through drops of virus placed directly into their <a href="https://www.nejm.org/doi/full/10.1056/NEJM199108293250903">nose</a>.</p> <p>These participants were then quarantined in a hotel and monitored closely to determine who became <a href="https://theconversation.com/stress-less-it-might-protect-you-from-covid-153361">ill</a>.</p> <p>One of the most important factors predicting who got sick was prolonged psychological <a href="https://journals.sagepub.com/doi/full/10.1177/1745691620942516">stress</a>.</p> <h2>Cortisol suppresses immunity</h2> <p>“Short-term stress” is stress that lasts for a period of minutes to hours, while “chronic stress” persists for several hours per day for <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5964013/#:%7E:text=Therefore%2C%20a%20major%20distinguishing%20characteristic,weeks%20or%20months%20%5B9%5D.">weeks or months</a>.</p> <p>When faced with a perceived threat, psychological or physical, the hypothalamus region of the brain sets off an alarm system. This signals the release of a surge of hormones, including adrenaline and <a href="https://www.embopress.org/doi/full/10.15252/msb.20209510">cortisol</a>.</p> <figure class="align-center "><img src="https://images.theconversation.com/files/616892/original/file-20240903-18-blrqoz.png?ixlib=rb-4.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px" srcset="https://images.theconversation.com/files/616892/original/file-20240903-18-blrqoz.png?ixlib=rb-4.1.0&amp;q=45&amp;auto=format&amp;w=600&amp;h=472&amp;fit=crop&amp;dpr=1 600w, https://images.theconversation.com/files/616892/original/file-20240903-18-blrqoz.png?ixlib=rb-4.1.0&amp;q=30&amp;auto=format&amp;w=600&amp;h=472&amp;fit=crop&amp;dpr=2 1200w, https://images.theconversation.com/files/616892/original/file-20240903-18-blrqoz.png?ixlib=rb-4.1.0&amp;q=15&amp;auto=format&amp;w=600&amp;h=472&amp;fit=crop&amp;dpr=3 1800w, https://images.theconversation.com/files/616892/original/file-20240903-18-blrqoz.png?ixlib=rb-4.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;h=593&amp;fit=crop&amp;dpr=1 754w, https://images.theconversation.com/files/616892/original/file-20240903-18-blrqoz.png?ixlib=rb-4.1.0&amp;q=30&amp;auto=format&amp;w=754&amp;h=593&amp;fit=crop&amp;dpr=2 1508w, https://images.theconversation.com/files/616892/original/file-20240903-18-blrqoz.png?ixlib=rb-4.1.0&amp;q=15&amp;auto=format&amp;w=754&amp;h=593&amp;fit=crop&amp;dpr=3 2262w" alt="Human brain illustration" /><figcaption><span class="caption">The hypothalamus sets off an alarm system in response to a real or perceived threat.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/hypothalamus-causes-vasoconstriction-illustration-medical-brain-435142264">stefan3andrei/Shutterstock</a></span></figcaption></figure> <p>In a typical stress response, <a href="https://www.sciencedirect.com/science/article/abs/pii/S147149060300173X">cortisol levels</a> quickly increase when stress occurs, and then rapidly drop back to normal once the stress has subsided. In the short term, cortisol suppresses inflammation, to ensure the body has enough energy available to respond to an <a href="https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.00245/full">immediate threat</a>.</p> <p>But in the longer term, chronic stress can be harmful. A Harvard University study <a href="https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2796097">from 2022</a> showed that people suffering from psychological distress in the lead up to their COVID infection had a greater chance of experiencing long COVID. They <a href="https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2796097">classified</a> this distress as depression, probable anxiety, perceived stress, worry about COVID and loneliness.</p> <p>Those suffering distress had close to a <a href="https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2796097">50% greater risk</a> of long COVID compared to other <a href="https://theconversation.com/being-stressed-out-before-you-get-covid-increases-your-chances-of-long-covid-heres-why-190649">participants</a>. Cortisol has been shown to be high in the most severe cases of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7102614/">COVID</a>.</p> <h2>Stress causes inflammation</h2> <p><a href="https://stories.uq.edu.au/imb/the-edge/inflammation/what-is-inflammation/index.html">Inflammation</a> is a short-term reaction to an injury or infection. It is responsible for trafficking immune cells in your body so the right cells are present in the right locations at the right times and at the right <a href="https://link.springer.com/article/10.1007/s12026-014-8517-0">levels</a>.</p> <p>The immune cells also store a memory of that threat to respond faster and more effectively the next <a href="https://theconversation.com/being-stressed-out-before-you-get-covid-increases-your-chances-of-long-covid-heres-why-190649">time</a>.</p> <p>Initially, circulating immune cells detect and flock to the site of <a href="https://www.nature.com/articles/ni1275">infection</a>. Messenger proteins, known as pro-inflammatory cytokines, are released by immune cells, to signal the danger and recruit help, and our immune system responds to neutralise the <a href="https://stories.uq.edu.au/imb/the-edge/inflammation/what-is-inflammation/index.html">threat</a>.</p> <p>During this response to the infection, if the immune system produces too much of these inflammatory chemicals, it can trigger symptoms such as nasal congestion and runny <a href="https://journals.sagepub.com/doi/full/10.1177/1745691620942516">nose</a>.</p> <h2>What about chronic stress?</h2> <p>Chronic stress causes persistently high cortisol secretion, which remains high even in the absence of an immediate <a href="https://theconversation.com/no-you-cant-blame-all-your-health-issues-on-high-cortisol-heres-how-the-hormone-works-203162">stressor</a>.</p> <p>The immune system becomes desensitised and unresponsive to this <a href="https://www.sciencedirect.com/science/article/abs/pii/S1043661816307435">cortisol suppression</a>, increasing low-grade “silent” inflammation and the production of pro-inflammatory cytokines (the messenger proteins).</p> <p>Immune cells become exhausted and start to <a href="https://www.fxmedicine.com.au/blog-post/adrenal-immune-connection">malfunction</a>. The body loses the ability to turn down the inflammatory <a href="https://journals.sagepub.com/doi/full/10.1177/1745691620942516">response</a>.</p> <p>Over time, the immune system changes the way it responds by reprogramming to a “<a href="https://www.unimelb.edu.au/newsroom/news/2021/april/how-stress-can-stop-immune-cells-in-their-tracks">low surveillance mode</a>”. The immune system misses early opportunities to destroy threats, and the process of recovery can take <a href="https://theconversation.com/being-stressed-out-before-you-get-covid-increases-your-chances-of-long-covid-heres-why-190649">longer</a>.</p> <h2>So how can you manage your stress?</h2> <p>We can actively strengthen our immunity and natural defences by managing our <a href="https://theconversation.com/stuck-in-fight-or-flight-mode-5-ways-to-complete-the-stress-cycle-and-avoid-burnout-or-depression-218599">stress levels</a>. Rather than letting stress build up, try to address it early and frequently by:</p> <p><strong>1) Getting enough sleep</strong></p> <p>Getting enough sleep reduces <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3132857/">cortisol levels</a> and inflammation. During sleep, the immune system <a href="https://link.springer.com/chapter/10.1007/978-1-4939-6578-6_12">releases</a> <a href="https://theconversation.com/sleep-wont-cure-the-coronavirus-but-it-can-help-our-bodies-fight-it-134674">cytokines</a>, which help fight infections and inflammation.</p> <p><strong>2) Taking regular exercise</strong></p> <p>Exercising helps the lymphatic system (which balances bodily fluids as part of the immune system) circulate and allows immune cells to monitor for threats, while sweating flushes <a href="https://www.healthline.com/nutrition/does-exercise-boost-immune-system">toxins</a>. Physical activity also lowers stress hormone levels through the release of positive brain <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7387807/">signals</a>.</p> <p><strong>3) Eating a healthy diet</strong></p> <p>Ensuring your diet contains enough nutrients – such as the B vitamins, and the full breadth of minerals like magnesium, iron and zinc – during times of stress has a positive impact on overall stress <a href="https://www.ncbi.nlm.nih.gov/pubmed/22782571">levels</a>. Staying hydrated helps the body to flush out <a href="https://theconversation.com/a-strong-immune-system-helps-ward-off-colds-and-flus-but-its-not-the-only-factor-99512">toxins</a>.</p> <p><strong>4) Socialising and practising meditation or mindfulness</strong></p> <p>These activities increase endorphins and serotonin, which improve mood and have <a href="https://www.sciencedirect.com/science/article/pii/S2949834123000351">anti-inflammatory effects</a>. Breathing exercises and meditation stimulate the parasympathetic nervous system, which calms down our stress responses so we can “reset” and reduce <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4940234/">cortisol levels</a>.<!-- 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/237456/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/sathana-dushyanthen-1169328">Sathana Dushyanthen</a>, Academic Specialist &amp; Lecturer in Cancer Sciences &amp; Digital Health| Superstar of STEM| Science Communicator, <a href="https://theconversation.com/institutions/the-university-of-melbourne-722">The University of Melbourne</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/im-feeling-run-down-why-am-i-more-likely-to-get-sick-and-how-can-i-boost-my-immune-system-237456">original article</a>.</em></p> </div>

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How long does immunity last after a COVID infection?

<p><em><a href="https://theconversation.com/profiles/lara-herrero-1166059">Lara Herrero</a>, <a href="https://theconversation.com/institutions/griffith-university-828">Griffith University</a> and <a href="https://theconversation.com/profiles/dr-wesley-freppel-1408971">Dr Wesley Freppel</a>, <a href="https://theconversation.com/institutions/griffith-university-828">Griffith University</a></em></p> <p>Nearly four years into the pandemic, Australia, like many other countries, is still seeing large numbers of <a href="https://nindss.health.gov.au/pbi-dashboard/">COVID cases</a>. Some 860,221 infections were recorded around the country in 2023, while 30,283 cases have already been reported in 2024.</p> <p>This is likely to be a significant underestimate, with fewer people testing and reporting than earlier in the pandemic. But the signs suggest parts of Australia are experiencing yet <a href="https://www.abc.net.au/news/2024-01-23/covid-19-case-numbers-from-australia-states-and-territories/103374656">another COVID surge</a>.</p> <p>While some lucky people claim to have never had COVID, many are facing our second, third or even fourth infection, often despite having been vaccinated. You might be wondering, how long does immunity last after a previous infection or vaccination?</p> <p>Let’s take a look at what the evidence shows.</p> <h2>B cells and T cells</h2> <p>To answer this question, we need to understand a bit about how <a href="https://theconversation.com/what-happens-in-our-body-when-we-encounter-and-fight-off-a-virus-like-the-flu-sars-cov-2-or-rsv-207023">immunity</a> to SARS-CoV-2 (the virus that causes COVID) works.</p> <p>After being infected or vaccinated, the immune system develops specific antibodies that can neutralise SARS-CoV-2. B cells remember the virus for a period of time. In addition, the immune system produces memory T cells that can kill the virus, and remain in the blood for some months after the clearance of the infection or a vaccination.</p> <p>A <a href="https://www.science.org/doi/full/10.1126/science.abf4063?rfr_dat=cr_pub++0pubmed&amp;url_ver=Z39.88-2003&amp;rfr_id=ori%3Arid%3Acrossref.org">2021 study</a> found 98% of people had antibodies against SARS-CoV-2’s spike protein (a protein on the surface of the virus that allows it to attach to our cells) one month after symptom onset. Six to eight months afterwards, 90% of participants still had these neutralising antibodies in their blood.</p> <p>This means the immune system should have recognised and neutralised the same SARS-CoV-2 variant if challenged within six to eight months (if an infection occurred, it should have resulted in mild to no symptoms).</p> <h2>But what about when the virus mutates?</h2> <p>As we know, SARS-CoV-2 has mutated over time, leading to the emergence of new variants such as alpha, beta, delta and omicron. Each of these variants carries mutations that are new to the immune system, even if the person has been previously infected with an earlier variant.</p> <p>A new variant likely won’t be <a href="https://www.science.org/doi/10.1126/science.adj0070">perfectly recognised</a> – or even <a href="https://www.cell.com/cell/pdf/S0092-8674(21)01578-6.pdf">recognised at all</a> – by the already activated memory T or B cells from a previous SARS-CoV-2 infection. This could explain why people can be so readily reinfected with COVID.</p> <p>A recent <a href="https://www.thelancet.com/article/S0140-6736(22)02465-5/fulltext#seccestitle10">review of studies</a> published up to the end of September 2022 looked at the protection conferred by previous SARS-CoV-2 infections.</p> <p>The authors found a previous infection provided protective immunity against reinfection with the ancestral, alpha, beta and delta variants of 85.2% at four weeks. Protection against reinfection with these variants remained high (78.6%) at 40 weeks, or just over nine months, after the previous infection. This protection decreased to 55.5% at 80 weeks (18 months), but the authors noted there was a lack of data at this time point.</p> <p>Notably, an earlier infection provided only 36.1% protection against a reinfection with omicron BA.1 at 40 weeks. Omicron has been described as an <a href="https://www.nature.com/articles/s41564-022-01143-7">immune escape variant</a>.</p> <p>A prior infection showed a high level of protection against severe disease (above 88%) up to 40 weeks regardless of the variant a person was reinfected with.</p> <h2>What about immunity after vaccination?</h2> <p>So far almost 70 million COVID vaccines <a href="https://www.health.gov.au/topics/covid-19/reporting">have been administered</a> to more than <a href="https://www.health.gov.au/resources/publications/covid-19-vaccine-rollout-update-12-january-2023?language=en">22 million people</a> in Australia. Scientists estimated COVID vaccines prevented around <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(22)00320-6/fulltext">14.4 million deaths</a> in 185 countries in the first year after they became available.</p> <p>But we know COVID vaccine effectiveness wanes over time. A <a href="https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2804451?utm_source=For_The_Media&amp;utm_medium=referral&amp;utm_campaign=ftm_links&amp;utm_term=050323">2023 review</a> found the original vaccines were 79.6% and 49.7% effective at protecting against symptomatic delta infection at one and nine months after vaccination respectively. They were 60.4% and 13.3% effective against symptomatic omicron at the same time points.</p> <p>This is where booster doses come into the picture. They’re important to keep the immune system ready to fight off the virus, particularly for those who are more vulnerable to the effects of a COVID infection.</p> <p>Plus, regular booster doses can provide immunity against different variants. COVID vaccines are constantly being <a href="https://mvec.mcri.edu.au/references/covid-19/">reviewed and updated</a> to ensure optimal protection against <a href="https://www.who.int/activities/tracking-SARS-CoV-2-variants">current circulating strains</a>, with the latest shot available designed to target <a href="https://www.health.gov.au/ministers/the-hon-mark-butler-mp/media/new-covid-19-vaccines-available-to-target-current-variants">the omicron variant XBB 1.5</a>. This is similar to how we approach seasonal flu vaccines.</p> <p>A <a href="https://www.nature.com/articles/s41598-023-50335-6">recent study</a> showed a COVID vaccination provides longer protection against reinfection than natural protection alone. The median time from infection to reinfection in non-vaccinated people was only six months, compared with 14 months in people who had received one, two or three doses of vaccine after their first infection. This is called <a href="https://www.science.org/doi/10.1126/science.abj2258">hybrid immunity</a>, and other research has similarly found it provides better protection than natural infection alone.</p> <p>It also seems timing is important, as receiving a vaccine too soon after an infection (less than six months) appears to be <a href="https://www.nature.com/articles/s41598-023-50335-6">less effective</a> than getting vaccinated later.</p> <h2>What now?</h2> <p>Everyone’s immune system is slightly unique, and SARS-CoV-2 continues to mutate, so knowing exactly how long COVID immunity lasts is complicated.</p> <p>Evidence suggests immunity following infection should generally last six months in healthy adults, and can be prolonged with vaccination. But there are exceptions, and all of this assumes the virus has not mutated so much that it “escapes” our immune response.</p> <p>While many people feel the COVID pandemic is over, it’s important we don’t forget the lessons we have learned. Practices such as wearing a mask and staying home when unwell can reduce the spread of many viruses, not only <a href="https://www.bmj.com/content/375/bmj-2021-068302">COVID</a>.</p> <p>Vaccination is not mandatory, but for older adults eligible for a booster under the <a href="https://www.health.gov.au/news/atagi-update-on-the-covid-19-vaccination-program">current guidelines</a>, it’s a very good idea.<!-- 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/221398/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><a href="https://theconversation.com/profiles/lara-herrero-1166059"><em>Lara Herrero</em></a><em>, Research Leader in Virology and Infectious Disease, <a href="https://theconversation.com/institutions/griffith-university-828">Griffith University</a> and <a href="https://theconversation.com/profiles/dr-wesley-freppel-1408971">Dr Wesley Freppel</a>, Research Fellow, Institute for Glycomics, <a href="https://theconversation.com/institutions/griffith-university-828">Griffith University</a></em></p> <p><em>Image credits: Getty Images</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/how-long-does-immunity-last-after-a-covid-infection-221398">original article</a>.</em></p>

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How biological differences between men and women alter immune responses – and affect women’s health

<p><a href="https://theconversation.com/profiles/helen-mcgettrick-1451122">Helen McGettrick</a>, <em><a href="https://theconversation.com/institutions/university-of-birmingham-1138">University of Birmingham</a></em> and <a href="https://theconversation.com/profiles/asif-iqbal-1451123">Asif Iqbal</a>, <em><a href="https://theconversation.com/institutions/university-of-birmingham-1138">University of Birmingham</a></em></p> <p>Most people will have heard the term “man flu”, which refers to men’s perceived tendency to exaggerate the severity of a cold or a similar minor ailment.</p> <p>What most people may not know is that, generally speaking, women mount stronger <a href="https://pubmed.ncbi.nlm.nih.gov/36121220/">immune responses</a> to infections than men. Men are <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1005374">more susceptible</a> to infections from, for example, HIV, hepatitis B, and <em>Plasmodium falciparum</em> (the parasite responsible for malaria).</p> <p>They can also have more severe symptoms, with evidence showing they’re more likely to be <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1005374">admitted to hospital</a> when infected with hepatitis B, tuberculosis, and <em>Campylobacter jejuni</em> (a bacteria that causes gastroenteritis), among others.</p> <p>While this may be positive for women in some respects, it also means women are at <a href="https://www.nature.com/articles/nri2815">greater risk</a> of developing chronic diseases driven by the immune system, known as immune-mediated inflammatory diseases.</p> <p>Here we will explore how biological factors influence immune differences between the sexes and how this affects women’s health. While we acknowledge that both sex and gender may affect immune responses, this article will focus on biological sex rather than gender.</p> <h2>Battle of the sexes</h2> <p>There are differences <a href="https://www.nature.com/articles/nri.2016.90">between the sexes</a> at every stage of the immune response, from the number of immune cells, to their degree of activation (how ready they are to respond to a challenge), and beyond.</p> <p>However, the story is more complicated than that. Our immune system evolves throughout our lives, learning from past experiences, but also responding to the physiological challenges of getting older. As a result, <a href="https://www.nature.com/articles/nri.2016.90">sex differences</a> in the immune system can be seen from birth through puberty into adulthood and <a href="https://academic.oup.com/jleukbio/advance-article/doi/10.1093/jleuko/qiad053/7190870">old age</a>.</p> <p>Why do these differences occur? The first part of answering this question involves the X chromosome. Females have two X chromosomes, while males have one X and one Y chromosome. The <a href="https://pubmed.ncbi.nlm.nih.gov/20651746/">X chromosome</a> contains the largest number of immune-related genes.</p> <p>The X chromosome also has <a href="https://link.springer.com/article/10.1007/s00018-020-03526-7">around 118 genes</a> from a gene family that are able to stop the expression of other genes, or change how proteins are made, including those required for immunity. These gene-protein regulators are known as microRNA, and there are only <a href="https://pubmed.ncbi.nlm.nih.gov/24808907/">two microRNA genes</a> on the Y chromosome.</p> <p>The X chromosome has <a href="https://www.genome.gov/about-genomics/fact-sheets/X-Chromosome-facts">more genes overall</a> (around 900) than the Y chromosome (around 55), so female cells have evolved to switch off one of their X chromosomes. This is not like turning off a light switch, but more like using a dimmer.</p> <p>Around <a href="https://bmcgenomics.biomedcentral.com/articles/10.1186/s12864-019-5507-6">15-25% of genes</a> on the silenced X chromosome are expressed at any given moment in any given cell. This means female cells can often express more immune-related genes and gene-protein regulators than males. This generally means a faster clearance of pathogens in females than males.</p> <p>Second, men and women have <a href="https://www.frontiersin.org/articles/10.3389/fimmu.2020.604000/full">varying levels</a> of different sex hormones. Progesterone and testosterone are broadly considered to limit immune responses. While both hormones are produced by males and females, progesterone is found at higher concentrations in non-menopausal women than men, and testosterone is much higher in men than women.</p> <p>The role of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6533072/">oestrogen</a>, one of the main female sex hormones, is more complicated. Although generally oestrogen <a href="https://www.sciencedirect.com/science/article/abs/pii/S000887491500026X?via%3Dihub">enhances immune responses</a>, its levels vary during the menstrual cycle, are high in pregnancy and low after menopause.</p> <p>Due in part to these genetic and hormonal factors, pregnancy and the years following are associated with heightened immune responses to external challenges such as infection.</p> <p>This has been regarded as an <a href="https://www.nature.com/articles/nri.2016.90">evolutionary feature</a>, protecting women and their unborn children during pregnancy and enhancing the mother’s survival throughout the child-rearing years, ultimately ensuring the survival of the population. We also see this pattern in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2628977/">other species</a> including insects, lizards, birds and mammals.</p> <h2>What does this all mean?</h2> <p>With women’s heightened immune responses to infections comes an increased risk of certain diseases and prolonged immune responses after infections.</p> <p>An <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3328995/">estimated 75-80%</a> of all immune-mediated inflammatory diseases <a href="https://pubmed.ncbi.nlm.nih.gov/32542149/">occur in females</a>. Diseases more common in women include multiple sclerosis, <a href="https://www.nature.com/articles/nri2815">rheumatoid arthritis</a>, lupus, Sjogren’s syndrome, and <a href="https://www.nature.com/articles/nri.2016.90">thyroid disorders</a> such as Graves disease.</p> <p>In these diseases, the immune system is continuously fighting against what it sees as a foreign agent. However, often this perceived threat is not a foreign agent, but cells or tissues from the host. This leads to tissue damage, pain and immobility.</p> <p>Women are also prone to chronic inflammation following infection. For example, after infections with <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5818468/">Epstein Barr virus</a> or <a href="https://www.liebertpub.com/doi/10.1089/jwh.2008.1193">Lyme disease</a>, they may go on to develop <a href="https://www.nhs.uk/conditions/chronic-fatigue-syndrome-cfs/">chronic fatigue syndrome</a>, another condition that affects more women than men.</p> <p>This is one possible explanation for the heightened risk among <a href="https://www.frontiersin.org/articles/10.3389/fresc.2023.1122673/full">pre-menopausal women</a> of developing long COVID following infection with SARS-CoV-2, the virus that causes COVID.</p> <p>Research has also revealed the presence of auto-antibodies (antibodies that attack the host) in patients with long COVID, suggesting it might be an <a href="https://www.sciencedirect.com/science/article/pii/S1568997221000550">autoimmune disease</a>. As women are more susceptible to autoimmune conditions, this could potentially explain the sex bias seen.</p> <p>However, the exact causes of long COVID, and the reason women may be at greater risk, are yet to be defined.</p> <p>This paints a bleak picture, but it’s not all bad news. Women typically mount <a href="https://pubmed.ncbi.nlm.nih.gov/24966191/">better vaccine responses</a> to several common infections (for example, influenza, measles, mumps, rubella, hepatitis A and B), producing higher antibody levels than men.</p> <p>One study showed that women vaccinated with half a dose of flu vaccine produced the same amount of antibodies compared to men vaccinated with <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/773453">a full dose</a>.</p> <p>However, these responses <a href="https://www.nature.com/articles/nri.2016.90">decline as women age</a>, and particularly <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3954964/">after menopause</a>.</p> <p>All of this shows it’s vital to consider sex when designing studies examining the immune system and treating patients with immune-related diseases.<!-- 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/208802/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/helen-mcgettrick-1451122">Helen McGettrick</a>, Reader in Inflammation and Vascular Biology, <a href="https://theconversation.com/institutions/university-of-birmingham-1138">University of Birmingham</a> and <a href="https://theconversation.com/profiles/asif-iqbal-1451123">Asif Iqbal</a>, Associate Professor in Inflammation Biology, <a href="https://theconversation.com/institutions/university-of-birmingham-1138">University of Birmingham</a></em></p> <p><em>Image credits: Getty Images</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/how-biological-differences-between-men-and-women-alter-immune-responses-and-affect-womens-health-208802">original article</a>.</em></p>

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Why does my back get so sore when I’m sick? The connection between immunity and pain

<p><em><a href="https://theconversation.com/profiles/joshua-pate-1399299">Joshua Pate</a>, <a href="https://theconversation.com/institutions/university-of-technology-sydney-936">University of Technology Sydney</a> and <a href="https://theconversation.com/profiles/mark-hutchinson-105409">Mark Hutchinson</a>, <a href="https://theconversation.com/institutions/university-of-adelaide-1119">University of Adelaide</a></em></p> <p>Have you ever wondered why your back aches when you’re down with the flu or a cold? Or COVID?</p> <p>This discomfort, common during many illnesses, is not just a random symptom. It’s a result of complex interactions between your immune system and your brain called the “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3314453/">neuroimmune synapse</a>”.</p> <p>A fascinating and yet-to-be-understood consequence of this conversation between the immune and brain systems during sickness is that it is particularly noticeable in the <a href="https://academic.oup.com/brain/article/145/3/1098/6370954">lower back</a>. This is thought to be one of the body’s most sensitive regions to neuroimmune threats.</p> <h2>Immunology basics</h2> <p>Our immune system is a double-edged sword. Yes, it fights off infections for us – but it also makes us acutely aware of the job it is doing.</p> <p>When our body detects an infection, our immune system releases molecules including signalling proteins called <a href="https://www.researchgate.net/publication/227831648_The_functions_of_cytokines_and_their_uses_in_toxicology">cytokines</a>. These proteins coordinate our immune system to fight off the infection and talk to our brain and spinal cord to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2740752/#:%7E:text=Production%20of%20proinflammatory%20cytokines%20induces,to%20depression%20in%20vulnerable%20individuals.">change our behaviour</a> and physiology.</p> <p>This can result in symptoms like fatigue, loss of appetite, fever and increased sensitivity to pain. Classically, we think of this as a beneficial behavioural change to help us conserve energy to fight off the infection. It’s why we often feel the need to rest and withdraw from our usual activities when we’re sick – and also why we are grumpier than usual.</p> <h2>Invisibly small changes</h2> <p>Part of this self-protective response is a change in how we perceive threats, including sensory stimuli.</p> <p>When we are sick, touch can become painful and muscles can ache. Many changes in behaviour and sensory systems are <a href="https://doi.org/10.1159/000521476">believed</a> to have origins at the nanoscale. When molecular changes occur in part of the brain linked to cognition or mood, we think and feel differently. If these neuroimmune synapse changes happen in the sensory processing regions of the brain and spinal cord, we feel more pain.</p> <p>Such sensory changes, known as <a href="https://www.iasp-pain.org/resources/fact-sheets/allodynia-and-hyperalgesia-in-neuropathic-pain/#:%7E:text=Allodynia%20is%20pain%20due%20to,stimulus%20that%20normally%20provokes%20pain.">allodynia and hyperalgesia</a>, can lead to heightened pain sensitivity, even in areas not directly affected by the infection – <a href="https://www.sciencedirect.com/science/article/abs/pii/S0889159114001731?via%3Dihub">such as the lower back</a>.</p> <h2>Immune memories</h2> <p>This immune response happens with a range of bacterial infections and viruses like COVID or the flu. In fact, the sick feeling we sometimes get after a vaccination is the good work our immune system is doing to contribute to <a href="https://theconversation.com/you-cant-get-influenza-from-a-flu-shot-heres-how-it-works-118916">a protective immune memory</a>.</p> <p>Some of that immune-cellular conversation also alerts our brains that we are sick, or makes us think we are.</p> <p>After some viral infections, the sick feeling persists longer than the virus. We are seeing a long-term response to COVID in some people, termed <a href="https://theconversation.com/when-does-covid-become-long-covid-and-whats-happening-in-the-body-when-symptoms-persist-heres-what-weve-learnt-so-far-188976">long COVID</a>.</p> <p>Women, who generally have a <a href="https://www.nature.com/articles/nri.2016.90">stronger immune response</a> than men, may be more likely to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7937378/">experience pain symptoms</a>. Their heightened immune response (while beneficial in resisting infections) also predisposes women to a higher risk of inflammatory conditions like <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7980266/">autoimmune diseases</a>.</p> <h2>When to worry and what to do</h2> <p>If the pain is severe, persistent, or accompanied by other concerning symptoms, seek medical attention. Mild to moderate pain is a common symptom during illness and we often notice this in the lower back. The good news is it usually subsides as the infection clears and the sickness resolves.</p> <p>While treating the underlying infection is crucial, there are also ways to dial down sickness-induced neuroimmune pain.</p> <p>Maintaining a diverse microbiome (the collection of microorganisms living in and on your body) by <a href="https://pubmed.ncbi.nlm.nih.gov/31704402/">eating well and getting outside</a> can help. Getting quality sleep, staying hydrated and minimising inflammation <a href="https://karger.com/bbe/article/97/3-4/197/821576/Sickness-and-the-Social-Brain-How-the-Immune">helps too</a>.</p> <p>Amazingly, there is <a href="https://pubmed.ncbi.nlm.nih.gov/34404209/">research</a> suggesting your grandmother’s traditional chicken broth recipe decreases the immune signals at the neuroimmune synapse.</p> <p>Scientists are also <a href="https://pubmed.ncbi.nlm.nih.gov/24799686/">showing</a> mindfulness meditation, cold water therapy and controlled breathing can drive profound cellular and molecular changes to help activate bodily systems like the autonomic nervous system and alter the immune response. These practices might not only help manage pain but also add an anti-inflammatory component to the immune response, reducing the severity and duration of sickness.</p> <p>Heat treatment (with a pack or hot water bottle) might <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8401625/">provide some relief</a> due to increased circulation. Over-the-counter pain relief maybe also be helpful but seek advice if you are taking other medications.</p> <h2>All in the mind?</h2> <p>Is this all mind over matter? A little of yes and a lot of no.</p> <p>The little of yes comes from <a href="https://pubmed.ncbi.nlm.nih.gov/26194270/">research</a> supporting the idea that if you expect your breathing, meditation and cold bath therapy to work, it may well make a difference at the cellular and molecular level.</p> <p>But by understanding the mechanisms of back pain during illness and by using some simple strategies, there is hope to manage this pain effectively. Always remember to seek medical help if your symptoms are severe or persist longer than expected. Your health and comfort are paramount.<!-- 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/207222/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/joshua-pate-1399299">Joshua Pate</a>, Senior Lecturer in Physiotherapy, <a href="https://theconversation.com/institutions/university-of-technology-sydney-936">University of Technology Sydney</a> and <a href="https://theconversation.com/profiles/mark-hutchinson-105409">Mark Hutchinson</a>, Professor, <a href="https://theconversation.com/institutions/university-of-adelaide-1119">University of Adelaide</a></em></p> <p><em>Image credits: Getty Images</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/why-does-my-back-get-so-sore-when-im-sick-the-connection-between-immunity-and-pain-207222">original article</a>.</em></p>

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Did COVID harm my immune system?

<p>So you’ve had COVID and have now recovered. You don’t have ongoing symptoms and luckily, you don’t seem to have developed <a href="https://theconversation.com/long-covid-how-researchers-are-zeroing-in-on-the-self-targeted-immune-attacks-that-may-lurk-behind-it-169911" target="_blank" rel="noopener">long COVID</a>.</p> <p>But what impacts has COVID had on your overall immune system?</p> <p>It’s early days yet. But growing evidence suggests there are changes to your immune system that may put you at risk of other infectious diseases.</p> <p>Here’s what we know so far.</p> <h2>A round of viral infections</h2> <p>Over this past winter, many of us have had what seemed like a <a href="https://theconversation.com/why-do-i-and-my-kids-get-so-many-colds-and-with-all-this-covid-around-should-we-be-isolating-too-179302" target="_blank" rel="noopener">continual round</a> of viral illness. This may have included COVID, <a href="https://www.who.int/health-topics/influenza-seasonal#tab=tab_1" target="_blank" rel="noopener">influenza</a> or infection with <a href="https://www.mayoclinic.org/diseases-conditions/respiratory-syncytial-virus/symptoms-causes/syc-20353098" target="_blank" rel="noopener">respiratory syncytial virus</a>. We may have recovered from one infection, only to get another.</p> <p>Then there is the re-emergence of infectious diseases globally such as <a href="https://theconversation.com/we-need-to-talk-about-monkeypox-without-shame-and-blame-188295" target="_blank" rel="noopener">monkeypox</a> or <a href="https://theconversation.com/the-latest-polio-cases-have-put-the-world-on-alert-heres-what-this-means-for-australia-and-people-travelling-overseas-188989" target="_blank" rel="noopener">polio</a>.</p> <p>Could these all be connected? Does COVID somehow weaken the immune system to make us more prone to other infectious diseases?</p> <p>There are <a href="https://www.sciencedirect.com/science/article/pii/B9780128009475000168?via%3Dihub" target="_blank" rel="noopener">many reasons</a> for infectious diseases to emerge in new locations, after many decades, or in new populations. So we cannot jump to the conclusion COVID infections have given rise to these and other viral infections.</p> <p>But evidence is building of the negative impact of COVID on a healthy individual’s immune system, several weeks after symptoms have subsided.</p> <h2>What happens when you catch a virus?</h2> <p>There are three possible outcomes after a viral infection:</p> <p>1) your immune system clears the infection and you recover (for instance, with <a href="https://www.healthychildren.org/English/health-issues/conditions/ear-nose-throat/Pages/Rhinovirus-Infections.aspx" target="_blank" rel="noopener">rhinovirus</a> which causes the common cold)</p> <p>2) your immune system fights the virus into “latency” and you recover with a virus dormant in our bodies (for instance, <a href="https://www.healthdirect.gov.au/chickenpox" target="_blank" rel="noopener">varicella zoster virus</a>, which causes chickenpox)</p> <p>3) your immune system fights, and despite best efforts the virus remains “chronic”, replicating at very low levels (this can occur for <a href="https://www.who.int/news-room/fact-sheets/detail/hepatitis-c" target="_blank" rel="noopener">hepatitis C virus</a>).</p> <p>Ideally we all want option 1, to clear the virus. In fact, most of us <a href="https://biosignaling.biomedcentral.com/articles/10.1186/s12964-022-00856-w" target="_blank" rel="noopener">clear SARS-CoV-2</a>, the virus that causes COVID. That’s through a complex process, using many different parts of our immune system.</p> <p>But international evidence suggests changes to our immune cells after SARS-CoV-2 infection may have other impacts. It may affect our ability to fight other viruses, as well as other pathogens, such as bacteria or fungi.</p> <h2>How much do we know?</h2> <p>An <a href="https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-021-02228-6" target="_blank" rel="noopener">Australian study</a> has found SARS-CoV-2 alters the balance of immune cells up to 24 weeks after clearing the infection.</p> <p>There were changes to the relative numbers and types of immune cells between people who had recovered from COVID compared with healthy people who had not been infected.</p> <p>This included changes to cells of the <a href="https://www.khanacademy.org/test-prep/mcat/organ-systems/the-immune-system/a/innate-immunity" target="_blank" rel="noopener">innate immune system</a> (which provides a non-specific immune response) and the <a href="https://www.ncbi.nlm.nih.gov/books/NBK21070/" target="_blank" rel="noopener">adaptive immune system</a> (a specific immune response, targeting a recognised foreign invader).</p> <p><a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1009742" target="_blank" rel="noopener">Another study</a> focused specifically on <a href="https://www.immunology.org/public-information/bitesized-immunology/cells/dendritic-cells" target="_blank" rel="noopener">dendritic cells</a> – the immune cells that are often considered the body’s “first line of defence”.</p> <p>Researchers found fewer of these cells circulating after people recovered from COVID. The ones that remained were less able to activate white blood cells known as <a href="https://www.britannica.com/science/T-cell" target="_blank" rel="noopener">T-cells</a>, a critical step in activating anti-viral immunity.</p> <p>Other studies have found different impacts on T-cells, and other types of white blood cells known as <a href="https://askabiologist.asu.edu/b-cell" target="_blank" rel="noopener">B-cells</a> (cells involved in producing antibodies).</p> <p>After SARS-CoV-2 infection, one study <a href="https://doi.org/10.1172/JCI140491" target="_blank" rel="noopener">found evidence</a> many of these cells had been activated and “exhausted”. This suggests the cells are dysfunctional, and might not be able to adequately fight a subsequent infection. In other words, sustained activation of these immune cells after a SARS-CoV-2 infection may have an impact on other inflammatory diseases.</p> <p><a href="https://www.nature.com/articles/s41392-021-00749-3#citeas" target="_blank" rel="noopener">One study</a> found people who had recovered from COVID have changes in different types of B-cells. This included changes in the cells’ metabolism, which may impact how these cells function. Given B-cells are critical for producing antibodies, we’re not quite sure of the precise implications.</p> <p>Could this influence how our bodies produce antibodies against SARS-CoV-2 should we encounter it again? Or could this impact our ability to produce antibodies against pathogens more broadly – against other viruses, bacteria or fungi? The study did not say.</p> <h2>What impact will these changes have?</h2> <p>One of the main concerns is whether such changes may impact how the immune system responds to other infections, or whether these changes might worsen or cause other chronic conditions.</p> <p>So more work needs to be done to understand the long-term impact of SARS-CoV-2 infection on a person’s immune system.</p> <p>For instance, we still don’t know how long these changes to the immune system last, and if the immune system recovers. We also don’t know if SARS-CoV-2 triggers other chronic illnesses, such as <a href="https://www.healthdirect.gov.au/chronic-fatigue-syndrome-cfs-me" target="_blank" rel="noopener">chronic fatigue syndrome</a> (myalgic encephalomyelitis). Research into this is ongoing.</p> <p>What we do know is that having a healthy immune system and being vaccinated (when a vaccine has been developed) is critically important to have the best chance of fighting any infection.</p> <p><strong>This article originally appeared on <a href="https://theconversation.com/ive-had-covid-and-am-constantly-getting-colds-did-covid-harm-my-immune-system-am-i-now-at-risk-of-other-infectious-diseases-188899" target="_blank" rel="noopener">The Conversation</a>.</strong></p> <p><em>Image: Shutterstock</em></p>

Body

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Arctic cod liver oil for immune vitality and healthy ageing

<p>Cod liver oil has been used for centuries in Scandinavian societies to help people, young and old, stay healthy throughout the year. Fresh cod liver oil is an excellent source of the omega-3 fatty acids EPA and DHA. Unlike most fish oil products, cod liver oil is unique in that it naturally contains a higher ratio of DHA to EPA, and typically delivers omega-3s in the triglyceride molecular form, the best form for their absorption by the body. Both EPA and DHA play vital roles in aspects of healthy ageing and immune function by influencing muscle and bone mass, mobility, energy, immune responses, and cognitive performance. Ensuring adequate intake of omega-3s with cod liver oil is an easy lifestyle change that can have a positive effect on many aspects of health. Here are some of the most notable omega-3 benefits of cod liver oil (a.k.a. CLO).</p> <p><strong>Omega-3s in CLO can support immune health via the gut </strong></p> <p>Having an overabundance of unhealthy gut bacteria can impair the immune system and accelerate the ageing process. Diet and lifestyle choices—including omega-3 consumption—are key factors for helping to establish a favourable environment for beneficial gut bacteria. Some studies have shown that increased consumption of omega-3s helps promote the growth of “good bacteria” in your gut, while other studies have shown a positive connection between adequate amounts of beneficial gut bacteria and a healthier immune response.</p> <p><strong>Omega-3 intake may influence muscle and bone strength</strong></p> <p>As we age, our immune system produces higher blood levels of inflammatory proteins that may impair muscle and bone health. Omega-3s supplements may support healthier blood levels of these age-associated proteins. Several studies report that people with higher dietary intake of omega-3s tend to have stronger muscles, increased exercise capacity, and denser bones. So, consider a cod liver oil for musculoskeletal health.</p> <p><strong>Omega-3s may help counter the effects of stress </strong></p> <p>Chronic stress increases the hormone cortisol, which can negatively impact immune health, especially if it remains elevated over a period of time. Some research studies have shown that omega-3 supplements may reduce the body’s production of cortisol. Furthermore, people who are “stressed out” tend to already have lower blood levels of the omega-3s EPA and DHA, potentially making it even more important for these individuals to consume supplemental omega-3s in order to keep from getting sick.</p> <p><strong>Omega-3s in CLO provide the building blocks for lasting, healthy skin </strong></p> <p>The skin is the largest organ in the body that also contains significant amounts of omega-3s. Due to years of exposure to ultraviolet light, toxins, and various irritants, the skin requires nutrients like omega-3s to help counter these stresses at the cellular level. The skin barrier is an important structure that protects the body and helps maintain a youthful appearance. Adequate intake of omega-3s supports skin cell functions, promotes the skin barrier, and increases the skin’s ability to retain water—a primary component of healthy skin. Because a portion of the omega-3s we consume eventually makes its way into the skin, these essential fats are vital for skin health.</p> <p><strong>Omega-3s in CLO support cardiovascular health</strong></p> <p>As we age, blood vessels stiffen, and blood pressure tends to increase, which places additional stress on the heart. Studies suggest that diets rich in omega-3s support healthy blood vessels, and several have reported that omega-3 supplements promote positive blood vessel health scores. Additionally, preliminary research suggests that omega-3 fatty acids may also help reduce oxidative stress within the blood vessels, promoting an optimal environment for the vasculature.</p> <p><strong>Choosing the right cod liver oil </strong></p> <p>Because most CLO is non-concentrated, these supplements offer omega-3s in the triglyceride molecular form, the same form in which EPA and DHA naturally exist in fish, and the form that ensures optimal digestion and absorption of omega-3s by the body. If you are ever unsure about the particular form of a CLO supplement (or any fish oil supplement), check the brand’s website or call their customer service department. This information is important, and should be easy for them to provide.</p> <p>It is also a good idea to select a CLO product that is from wild-caught sustainable cod, and that does not contain synthetic additives. Arctic cod from Norway are often sourced using small boats owned and operated by independent cod fishermen, so demand for Arctic cod supports local fishing communities. Also, these boats leave and return daily which means they have a much shorter transport time from catch to processing than larger trawling vessels. This short time helps maximise fish oil freshness, and the efficacy of the omega-3 fats in Arctic Cod Liver Oil.</p> <p>In closing, CLOs have many unique benefits, but do not take our word for it – try it and see for yourself.</p> <p><strong>Use the code HEALTHYME when ordering online and get your delivery freight free. Only for a limited time. Order at </strong><a href="https://bit.ly/3FkXAFE" target="_blank" rel="noopener"><strong>TheraHealth.com.au</strong></a><strong> or find a local </strong><a href="https://bit.ly/3vJY054" target="_blank" rel="noopener"><strong>stockist near you here</strong></a><strong>.</strong></p> <p><img class="alignnone size-full wp-image-59001" src="https://oversixtydev.blob.core.windows.net/media/2022/05/Author_O60.jpg" alt="" width="1280" height="440" /></p> <p><em><strong>This is a sponsored article produced in partnership with <a href="https://bit.ly/3FkXAFE" target="_blank" rel="noopener">Thera Health</a>.</strong></em></p> <p><em><strong>Image: Shutterstock</strong></em></p>

Body

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Three reasons you haven’t caught Covid yet

<p dir="ltr">Most of us have been in close contact with someone who contracted Covid but never tested positive ourselves.</p> <p dir="ltr">It raises questions as to why you would not test positive yourself despite being in the same room as a positive case, sharing food and drink despite how infectious the virus is.</p> <p dir="ltr">There are three possible reasons as to why you still haven’t caught Covid, despite the situation leaving doctors stumped. </p> <p dir="ltr">Australian National University lecturer and epidemiologist Dr Katrina Roper helps explain the three main reasons why some don’t test positive. </p> <p dir="ltr"><strong>Common cold</strong></p> <p dir="ltr">Before Covid, we’d all be exposed to the common cold which would help build immunity against other viruses. </p> <p dir="ltr">“Having a prior infection to another cold virus can confer some protection to Covid, or other respiratory viruses,” Dr Roper told <a href="https://www.news.com.au/lifestyle/health/health-problems/a-doctor-explains-why-you-havent-caught-covid-yet/news-story/d57a08a08278abf27f43c29fcfe87196" target="_blank" rel="noopener">news.com.au</a>.</p> <p dir="ltr">”Exposure to other respiratory viruses can prime parts of the immune system, leading to better defence against infection by the SARS CoV-2 infection”.</p> <p dir="ltr">Research published in the Nature Communications journal in January 2022, confirmed the theory that being exposed to Covid won’t always cause an infection.</p> <p dir="ltr">“Being exposed to the SARS-CoV-2 virus doesn’t always result in infection, and we’ve been keen to understand why,” lead author Dr Rhia Kundu wrote.</p> <p dir="ltr">“We found that high levels of pre-existing T cells, created by the body when infected with other human coronaviruses like the common cold, can protect against COVID-19 infection.”</p> <p dir="ltr">Immunologist Professor Stuart Tangye insists that there’s also a possibility that you were infected with Covid but you didn’t know it. </p> <p dir="ltr"><strong>Your immune system</strong></p> <p dir="ltr">When it comes to avoiding Covid it could be that your immune system is pretty strong, or the vaccine worked better for you. </p> <p dir="ltr">Dr Roper however did point out that it could also all depend on the individuals’ circumstance - such as their age, weight and how healthy they are.</p> <p dir="ltr">She noted that even the healthiest of people could still have weakened immune systems - citing professional athletes who push themselves and in turn feel worse afterwards. </p> <p dir="ltr"><strong>The exposure</strong></p> <p dir="ltr">Again, everyone has been exposed differently to Covid and while some may have contracted it, you didn’t. </p> <p dir="ltr">The circumstances of where you are could be affected such as a large house but only two people living there, giving you ample space to stay away despite sharing the same areas.</p> <p dir="ltr"><strong>Genetics</strong></p> <p dir="ltr">Professor Tangye suggested a fourth reason as to why you haven’t contracted Covid despite your exposure.</p> <p dir="ltr">Put simply, your genetics. </p> <p dir="ltr">“There are going to be people who are less susceptible to viral infection because they have differences in their genes, such as genes that are important for viral entry into your cells,” he said.</p> <p dir="ltr"><em>Image: Shutterstock</em></p>

Caring

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I just recovered from Omicron – how long does my immunity last?

<div class="copy"> <p>If you recently recovered from an <a rel="noreferrer noopener" href="https://cosmosmagazine.com/health/covid/omicron-update-170122/" target="_blank">Omicron infection</a>, do you now have free rein to do whatever you want without risk of reinfection? And if so, for how long?</p> <p>Two main factors affect how well your acquired immunity after Omicron infection will protect you. </p> <p>First, your antibody levels. “If high levels of neutralising antibodies are elicited to Omicron following infection, then we would expect to see some level of protection against reinfection with Omicron, but this is likely to be short-lived,” says Professor Gilda Tachedjian, a virologist at the Burnet Institute and past president of the Australian Virology Society.</p> <p>Generally, a more severe infection generates a higher level of antibodies than an asymptomatic infection, explains Professor Anthony Cunningham, an infectious diseases physician and clinical virologist at the University of Sydney. But when the level of neutralising antibodies begins to drop, your likelihood of reinfection rises.</p> <p>It’s simply too early to know how long Omicron immunity will last, he says.</p> <p>From vaccine studies, we know that antibody levels begin to drop after three to six months. A <a rel="noreferrer noopener" href="https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247(21)00219-6/fulltext" target="_blank">recent study</a> published in <em>The Lancet</em> estimated that reinfection by SARS-CoV-2 under endemic conditions would likely occur between three months and five years after peak antibody response.</p> <p>Almost certainly, Cunningham says, there will be a lot of individual variation, similar to what has been observed with previous strains. This variation depends on the severity of the disease you experienced, and whether you have had a vaccine.</p> <p>The second factor: emerging variants. Our waning antibodies may not be able to target any new variants that come along. The Omicron variant, for example, largely evades immunity from past infection and vaccines. A recent <a rel="noreferrer noopener" href="https://www.imperial.ac.uk/mrc-global-infectious-disease-analysis/covid-19/report-49-Omicron/" target="_blank">report</a> from Imperial College London estimates that the risk of reinfection with Omicron is 5.4 times greater than that of the Delta variant.</p> <p>“The most likely outcome is that you won’t get re-infected with Omicron because the expectation is that the Omicron wave will decline, but then the greatest risk is that another strain comes along,” says Cunningham. “It all depends on what type of strain comes next.”</p> <p>Even if you have had a recent Omicron infection, don’t throw your mask away, warns Cunningham: “The more virus circulates in the world, the more likely it is that we’ll see new strains.”</p> <p>Although protection from reinfection might not last for long, experts think T-cells might come to the rescue.</p> <p>While antibodies directly bind and neutralise virions, preventing an infection, T-cells activate once the infection is established. They target and kill virus-infected cells, helping to clear the infection and reduce its severity. This arm of the immune response tends to be broader than antibodies – and thus more likely to recognise variants, and to last longer, Tachedjian explains.</p> <p>“Hopefully, you will be asymptomatic or have a less severe disease [the second time around].”</p> <em>Image credits: Getty Images </em></div> <div id="contributors"> <p><em>This article was originally published on <a href="https://cosmosmagazine.com/health/covid/immunity-after-omicron-infection/">cosmosmagazine.com</a> and was written by Dr Manuela Callari. </em></p> </div>

Body

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COVID concerns drive supplement and vitamin use

<div> <p><em>Image: Getty </em></p> <p><span>Sales of complementary medicines have been driven up by COVID fears, but immune boosting claims for them are doing more harm than good. </span></p> <div class="copy"> <p>In an <a rel="noopener" href="https://www.nps.org.au/australian-prescriber/articles/the-safety-of-commonly-used-vitamins-and-minerals" target="_blank">article</a> published today in <em>Australian Prescriber, </em>University of Queensland Adjunct Associate Professor of Pharmacology Geraldine Moses has warned of major potential harms associated with the use of dietary supplements.</p> <p>“One reason for the persistent popularity of vitamins and minerals is the perception that they are harmless,” says Moses. But that perception masks a troublesome reality.</p> <p>“When it comes to complementary medicines, most consumers are only given information about the possible benefits of these products, and little if anything about risk – and there’s always potential risk.”</p> <p>The advice comes as supplement use is soaring. In July, a US survey claimed that nearly 30% of Americans are now taking more supplements than they were before the COVID-19 pandemic. Commissioned by the US health non-profit <a rel="noopener" href="https://www.samueli.org/" target="_blank">Samueli Foundation</a>, the <a rel="noopener" href="https://theharrispoll.com/" target="_blank">Harris Poll</a> concluded that 76% of US citizens were taking supplements.</p> <p>The article in <em>Australian Prescriber</em> discusses six potential harms of using dietary supplements:</p> <ul> <li>They can have <strong>adverse effects</strong>, particularly at high doses.</li> <li>They can <strong>interact with other medicines</strong>.</li> <li>They <strong>cost money</strong>, which may be better spent on other things.</li> <li>Time spent taking dietary supplements may delay <strong>more effective treatments</strong>.</li> <li>They may <strong>bring false hope</strong> and disappointment.</li> <li>By taking dietary supplements, people <strong>add to the number of medicines they are taking</strong>, increasing the risk of medication error, interactions and adverse effects.</li> </ul> <p>The US survey was small and not based on a probability sample, so more research is required to build an accurate picture. But the trend it highlights is supported by evidence globally of an upturn in supplement use.</p> <p>Accurate figures for Australia are hard to obtain, but market researchers <a rel="noopener" href="https://www.ibisworld.com/au/industry/online-vitamin-supplement-sales/4091/" target="_blank">report</a> that sales of vitamins and supplements soared during the pandemic. </p> <p>The trend suggests that pandemic-related fear may be driving the use of these products, which some experts say are not regulated or evidenced as rigorously as <a rel="noopener" href="https://www.tga.gov.au/registered-medicines" target="_blank">registered medicines</a>. And while the pandemic may have bolstered supplement sales, the scale of their use has always been profound: in 2018, around <a rel="noopener" href="http://www.roymorgan.com/findings/7956-australian-vitamin-market-december-2018-201904260734" target="_blank">a third of Australians</a> – 8.3 million people – reported buying supplements, according to Roy Morgan.</p> <h4><strong>Supplementary harms?</strong></h4> <p>Supplements can be benign and are critical for people with particular conditions or deficiencies, but there are notable cases in which they’ve been shown to cause long-term damage.</p> <p>Just last week, doctors at a Sydney liver transplant centre <a rel="noopener" href="https://insightplus.mja.com.au/2021/27/drug-related-liver-injury-call-for-better-regulation-of-supplements/" target="_blank">went public with concerns</a> that drug-induced liver injuries linked to dietary and herbal supplements were on the rise. </p> <p>Their <a rel="noopener" href="https://www.mja.com.au/journal/2021/215/6/drug-induced-liver-injury-australia-2009-2020-increasing-proportion-non" target="_blank">study</a>, which spanned 2009 to 2020, found that the proportion of drug-induced liver injuries that were caused by supplements (as opposed to things such as paracetamol and other medications) rose from 15% in 2009–11 to 47% in 2018–20. </p> <p>“We observed a link to bodybuilding and weight-loss supplements as has been seen in reports internationally, but also a link to traditional Chinese medicines,” says co-author Simone Strasser, president of the Gastroenterological Society. “Both groups of supplements are rising in popularity in Australia.”</p> <p>Strasser says that in many cases supplement-related drug-induced liver injuries (DILIs) were potentially severe: while 90-day transplant-free survival was 74% for liver injuries caused by paracetamol, it was 59% for those caused by supplements. </p> <p>“There’s an old saying that the difference between a drug and a poison is the dose,” says Moses. “What many people don’t realise is that high doses of some supplements can be dangerous.”</p> <p>Moses says that because consumers aren’t aware of the potential toxicity of supplements, they may be skirting perilously close to the line without even knowing.</p> <p>“Vitamin B6 is the classic one,” Moses says. “In Australia, the toxic dose is considered to be 200mg a day or more, and lots of people that I see now in hospital will be on four products with 50mg in each one, so they’re at the toxic dose, but they’re completely unaware of that.”</p> <p>The authors of the liver-damage study have expressed concern that so many supplements are escaping regulatory oversight by the Therapeutic Goods Administration (TGA), not least, Strasser says, because “not infrequently these compounds were purchased online, bypassing the Australian regulatory system”.</p> <p>Strasser adds that because reporting adverse events associated with supplements to the TGA is voluntary, many severe adverse reactions go unreported.</p> <h4><strong>Health anxiety drives demand</strong></h4> <p>As the pandemic progresses, reports of health anxiety <a rel="noopener" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7239023/" target="_blank">naturally rise</a>. A July 2020 <a rel="noopener" href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0236562" target="_blank">study</a> among 5,070 adult Australians of varying ages and from various locations found that 25% were very or extremely worried about contracting COVID-19, and around half (52%) were worried about family and friends contracting the disease.</p> <p>“When people are fearful, especially now with COVID, they will reach out and do whatever they can to assuage their anxiety, including taking natural health products,” Moses says. </p> <div class="newsletter-box"> <p class="h2"><strong>But do supplements work as promised?</strong></p> </div> <p>Ken Harvey, a professor at Bond University’s school of Health Sciences and Medicine and an outspoken critic of pharmaceutical marketing, says that supplements can be helpful in specific cases. For example, pregnant women are encouraged to take folic acid to reduce the risk of foetal defects, and older people may need certain nutritional supplements to make up for deficiencies caused by poor diet, lack of activity and a lack of sunlight. </p> <p>But Harvey says most Australians can get enough of what they need from a reasonably healthy diet, so any vitamin they take will simply be filtered out by the kidneys and excreted in urine, because the body already has enough. </p> <p>Meanwhile, social media and wellness ‘influencers’ are patently contributing to the problem. A 2020 <a rel="noopener" href="https://aacijournal.biomedcentral.com/articles/10.1186/s13223-020-00474-6" target="_blank">study</a> in <em>BMC Allergy, Ashthma and Clinical Immunology </em>found that use of the popular Instagram hashtag #immunebooster increased by over 46% between 15 April and 15 May 2020.</p> <h4><strong>The myth of “immune-boosting” products</strong></h4> <p>One of the most touted phrases by both wellness influencers and supplement brands is ‘immune-boosting’, a term that had become synonymous with “wellness” even before the global pandemic. But how accurate is the term ‘immune-boosting’?</p> <p>Well, not very. According to Harvey, the immune-boosting myth is based on the fact that a lack of vitamins and minerals is known to<em> </em>weaken immunity, for example among malnourished populations. But Harvey says that in Australia, “there is no good evidence of widespread vitamin deficiencies in the population”.</p> <p>In fact, the idea of immune-boosting is based on a misconception about how the immune system works. The immune system is <a rel="noopener" href="https://www.cedars-sinai.org/blog/boosting-your-immune-system.html" target="_blank">better off balanced</a> than boosted – if it could be boosted by supplements (<a rel="noopener" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6673706/#B7" target="_blank">which it can’t</a>), users would experience symptoms of an immune response, such as fever and a runny nose, and in extreme cases would end up very sick.</p> <p>“To ‘boost’ your immune system against specific diseases, you’ve got to either catch one, or you’ve got to be vaccinated,” Harvey says, adding that consumers often buy supplements under the mistaken belief – promoted by some brands – that they will offer immunological benefits.</p> <p>Even more alarming, there is <a rel="noopener" href="https://pubmed.ncbi.nlm.nih.gov/28911953/" target="_blank">evidence</a> that some people may use ‘immune-boosting’ natural remedies as an alternative to vaccinations against viral conditions such as the flu, meaning the immune-boosting myth could hamper the fight against disease.</p> <p>Harvey says the TGA has regulated against advertising that promotes immune-boosting products by reference to the pandemic – but there’s a major loophole, because products can still be marketed as ‘immune-boosting’, provided they don’t mention COVID-19. </p> <h4><strong>So, how <em>are</em> supplements regulated?</strong></h4> <p>Under the TGA’s classification process, there are two major categories of medicines. Registered medicines include all prescription medications and most over-the-counter (OTC) medicines. Prescription medications are considered higher risk, and OTC medicines a lower but still palpable risk, so all registered medicines are assessed by the TGA for quality, safety <em>and </em>efficacy.</p> <p>Efficacy, in pharmacological terms, refers to the ability of a drug to provide the benefits to which it claims, including establishing the dosage required to provide that benefit. <a rel="noopener" href="https://www.nps.org.au/australian-prescriber/articles/efficacy-effectiveness-efficiency" target="_blank">Efficacy is established during clinical trials</a>.</p> <p>Complementary medicines such as supplements fall into the category of <a rel="noopener" href="https://www.tga.gov.au/listed-medicines" target="_blank">listed medicines</a>, which generally contain well-known, low-risk ingredients with long histories of use, such as vitamin and mineral products and sunscreens. These medicines are those that the TGA considers to be generally benign or low risk, so, “listed medicines do not undergo a full pre-market assessment of safety, quality and efficacy,” according to the TGA.</p> <p>The TGA <em>does</em> do yearly post-marketing surveillance on around 150 of the thousands of listed medicines on the Australian market, the results of which can be found in its <a rel="noopener" href="https://www.tga.gov.au/annual-performance-statistics-reports" target="_blank">annual performance statistics reports</a>. </p> <p>A review of the performance statistics over the five years from 2015 to 2020 reveals that around 75% to 80% of the listed medicines tested are found to breach compliance in some way, which would appear to point to what Harvey refers to as a “light-touch regulatory process” for listed medicines.</p> <h4><strong>Where to now?</strong></h4> <p>Approached for comment, the TGA informed <em>Cosmos </em>that enhancements to the listed medicines post-market compliance scheme are coming. </p> <p>But the supplement sector has always been resilient, offering an alluring alternative to Western medicine, whether because the supplements are perceived as low risk, or because of an inherent distrust of public-health messaging.</p> <p>“They [the TGA] have a pretty tough job to do, trying to cover every possible pharmaceutical product throughout Australia,” Moses says. “But I certainly think that with complementary medicines we could do a better job if we required manufacturers to provide consumers with information about potential risks.”</p> <p>Strasser says that a lack of public education is hampering both the TGA and the medical profession’s ability to clamp down on unsafe supplement use.</p> <p>“There is still a perception that supplements are natural and therefore healthy,” she says. “Time after time, patients who experience severe DILI are incredibly surprised that something they purchase over the counter or online with the aim of improving their health could have harmed them.”</p> <!-- Start of tracking content syndication. Please do not remove this section as it allows us to keep track of republished articles --> <img id="cosmos-post-tracker" style="opacity: 0; height: 1px!important; width: 1px!important; border: 0!important; position: absolute!important; z-index: -1!important;" src="https://syndication.cosmosmagazine.com/?id=160279&amp;title=COVID+concerns+drive+supplement+use" alt="" width="1" height="1" /> <!-- End of tracking content syndication --></div> <div id="contributors"> <p><a href="https://cosmosmagazine.com/health/dangers-dietary-supplements/">This article</a> was originally published on <a href="https://cosmosmagazine.com">Cosmos Magazine</a> and was written by <a href="https://cosmosmagazine.com/contributor/amalyah-hart">Amalyah Hart</a>. </p> </div> </div>

Food & Wine

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Government announces shortened booster window

<p dir="ltr">The federal government has announced that the timeframe between the second COVID-19 vaccine and the booster shot has been shortened, from five months to four. The change will come into effect on January 4.</p> <p dir="ltr">This is an additional reduction, following an initial interval of six months in between shots. Furthermore, on January 31, the gap between shots will be reduced to just three months.</p> <p dir="ltr">These changes will enable millions of Australians to receive their booster shots, which are increasingly being seen as necessary to resist the Omicron strain and maintain immunity amidst rising cases across the country, far sooner.</p> <p dir="ltr">This includes over 60s, many of whom were not fully vaccinated until late in the year due to eligibility criteria. Tony Blakeley, an epidemiologist from the University of Melbourne, described the five-month gap between the second and third shots as “bordering on unethical”, particularly for older Australians who received the AstraZeneca vaccine.</p> <p dir="ltr">“AstraZeneca recipients are often 60-plus, they're often more vulnerable, yet they had a vaccine where they had to wait three months between the first and second dose and now they're not eligible,” he explained.</p> <p dir="ltr">The change follows advice from expert vaccination group ATAGI and is in response to the recent spike in cases as the Omicron variant spreads throughout the community. On Friday, Victoria recorded 2095 new cases and eight deaths, while NSW recorded 5612 and one death.</p> <p dir="ltr">Health Minister Greg Hunt explained that cutting the interval down would ensure roughly 7.5 million Australians would be eligible to receive a booster shot by early January, whereas as of Friday, only 3.2 million were eligible.</p> <p dir="ltr">Once the interval is reduced further at the end of January, about 16 million Australians will be eligible to receive their third vaccine. In a press conference on Friday, Mr Hunt said, “These dates have been set out of an abundance of caution to give Australians early continued protection.”</p> <p dir="ltr"><em>Image: Rohan Thomson/Getty Images</em></p>

News

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Meditation could boost your immune system

<p><span style="font-weight: 400;">A </span><a rel="noopener" href="https://www.scimex.org/newsfeed/how-meditation-could-help-boost-the-immune-system" target="_blank"><span style="font-weight: 400;">new study</span></a><span style="font-weight: 400;"> has connected intensive meditation with altered behaviour of over 200 genes tied to immunity, with their findings suggesting that meditation may be beneficial for those with a weakened immune system.</span></p> <p><span style="font-weight: 400;">The research, recently published in the journal </span><em><a rel="noopener" href="https://www.pnas.org/content/118/51/e2110455118" target="_blank"><span style="font-weight: 400;">Proceedings of the National Academy of Sciences (PNAS)</span></a></em><span style="font-weight: 400;">, involved analysing blood samples from 106 volunteers who participated in an intensive Samyama meditation retreat. The participants spent eight days in complete silence, followed a strict vegan diet and regular sleep schedule, and meditated for more than ten hours each day.</span></p> <p><span style="font-weight: 400;">Several samples were taken from each participant, including one two months before the retreat, another five weeks before, two immediately before and after the retreat, and a final sample three months after it ended.</span></p> <p><span style="font-weight: 400;">After analysing the gene expression in the samples, the team found that there were “distinct” alterations in how genes were expressed after participants meditated.</span></p> <p><span style="font-weight: 400;">In particular, they found that 220 genes tied to immunity had higher levels of expression without an increase in inflammation.</span></p> <p><span style="font-weight: 400;">Sixty-eight of these genes were also tied to signalling proteins called interferons. These proteins help our immune systems to identify viruses and trigger immune cells to fight viral cells, stopping them from multiplying.</span></p> <p><span style="font-weight: 400;">“These findings suggest that meditation has an immediate impact on immune cells and genes,” the authors wrote.</span></p> <p><span style="font-weight: 400;">They also discovered that there wasn’t an increase in inflammation</span></p> <p><span style="font-weight: 400;">Though many studies have found that meditation has a positive impact on our health, this new research investigates what happens inside human cells when we meditate to explain why we experience these positive effects.</span></p> <p><span style="font-weight: 400;">By examining the gene expression before and after meditation, the authors suggest that meditation could be helpful for treating conditions characterised by a weakened immunity and persistent inflammation.</span></p> <p><span style="font-weight: 400;">“Together, these results make meditation an effective behavioural intervention for treating various conditions associated with a weakened immune system,” they concluded.</span></p> <p><em><span style="font-weight: 400;">Image: Getty Images</span></em></p>

Mind

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Can you mix and match COVID-19 vaccine and booster shot brands?

<p><em>Image: Shutterstock</em></p> <p>In the early months of Australia’s COVID-19 booster program, the Pfizer shot was essentially the only option, but now that is no longer the case.</p> <p>The Moderna vaccine has now been approved by the Therapeutic Goods Administration and the Australian Technical Advisory Group on Immunisation (ATAGI) for booster purposes.</p> <p>Emily Edwards from the Department of Immunology and Pathology at Monash University said additional vaccines being introduced into the booster program was welcome news.</p> <p>“The more vaccines that we have approved, the less supply chain issues that we're going to come across, which means that then we can keep up the consistent provision of vaccination to the community,” she said last week.</p> <p>ATAGI have advised that booster doses can now be provided from five months after someone’s second dose, rather than six months given the likelihood of ongoing transmission of the Omicron and Delta variants.</p> <p>So, is it safe to mix and match?</p> <p>Health experts advice that it is safe to mix and match.</p> <p>“The scientific literature is saying that it is safe to mix and match vaccines,” Dr Edwards said.</p> <p>“The evidence coming out is saying that there's no issue in having a booster that is different to what your two primary doses are.”</p> <p>There are suggestions that having a different booster brand could even give you greater immunity. Chris Moy, vice president of the Australian Medical Association, said “there’s a long history of being able to mix vaccines for the same condition, and in fact, possibly getting more bang for your buck in doing so”.</p> <p>“But it doesn't really make a lot of difference. Basically, these booster shots all seem to do the right thing in terms of being able to drive up that immunity,” he said.</p> <p>The advice is mostly coming from studies that compare mixing vaccines between the first and second dose. Dr Moy said the most important thing isn’t the brand of booster you get, but just getting one to begin with.</p> <p>“I think we're quibbling about minor differences between the vaccines. All the vaccines are very good and they've all got their pros and cons ... but overall, these are very, very minor. It's the difference between an LG versus a Samsung versus a Sony,” he said.</p> <p>“If people are worried enough they can shop around, but sometimes what's more important is actually to go get the darn injection in your arm.”</p> <p>Anyone with concerns should seek medical advice, Dr Edwards added.</p> <p>The advice is mostly coming from studies that compare mixing vaccines between the first and second dose. </p> <p><strong>What about AstraZeneca?</strong></p> <p>AstraZeneca can be used as a booster for people who had it for previous shots and didn't encounter an adverse reaction, but it is not preferred.</p> <p>Those who had a significant adverse reaction after a previous mRNA vaccine – the class of vaccine that Pfizer and Moderna belong to - could also use it.</p> <p>“It can be used as a booster, but only in rare circumstances and only for people that had AstraZeneca for the first two shots,” Dr Moy said.</p> <p><strong>How many people have had the booster so far?</strong></p> <p>As of Thursday last week, more than 600,000 people in Australia had already received a booster shot.</p> <p>A survey by the Australian National University released on Thursday found 70 per cent of respondents would ‘definitely’ be receiving a booster shot.</p>

Body

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Our bodies or infection: What actually kills us?

<p><span style="font-weight: 400;">A growing body of evidence suggests that our immune systems may be responsible for the deaths of others from infectious diseases such as COVID-19.</span></p> <p><span style="font-weight: 400;">Since a virus doesn’t “want” to kill the host - us - and has a sole goal of surviving and reproducing, it might be that our bodies are the cause of death following infection.</span></p> <p><span style="font-weight: 400;">In an effort to stop the virus in its tracks, the body can harm major organs that include the lungs and heart. This has led some doctors to focus on reducing the immune response of infected patients in order to save them.</span></p> <p><span style="font-weight: 400;">But, the question still remains: what’s the point of having an immune system if it kills us?</span></p> <p><span style="font-weight: 400;">The answer may be to do with our evolutionary history and require us to think about immunity in terms of communication and behaviour alongside biology. And, the more that researchers can understand how our immune system originated, the more likely they are to develop better ways of dealing with it.</span></p> <p><strong>What does behaviour have to do with immune systems?</strong></p> <p><span style="font-weight: 400;">This ties into the concept of the behavioural immune system. Feeling disgusted or repulsed by something because it makes us feel like it poses a threat to our health is just one example.</span></p> <p><span style="font-weight: 400;">Animals do this too, with </span><a href="https://pubmed.ncbi.nlm.nih.gov/25256957/"><span style="font-weight: 400;">research showing</span></a><span style="font-weight: 400;"> that some animals avoid others that show signs of illness.</span></p> <p><span style="font-weight: 400;">But, unlike other animals, humans are likely to be compassionate towards those with symptoms of illness or injury, according to more recent </span><a href="https://pubmed.ncbi.nlm.nih.gov/27405223/"><span style="font-weight: 400;">theoretical research</span></a><span style="font-weight: 400;">.</span></p> <p><span style="font-weight: 400;">According to this theory, that is why people tend to exclaim when feeling pain, rather than silently moving away.</span></p> <p><span style="font-weight: 400;">Some psychologists argue that this is because immune responses involve communication just as much as they do self-maintenance, since people who have received care in the past have probably tended to do better than those trying to survive on their own.</span></p> <p><span style="font-weight: 400;">In evolutionary literature, these kinds of displays of pain are referred to as kinds of “signals”, which can be faked to exploit the world around us.</span></p> <p><strong>Faking it is an evolutionary thing</strong></p> <p><span style="font-weight: 400;">How many times have you faked being in pain or sick to avoid an obligation? If your answer is ‘all the time’, you’re not alone. People feign these signals frequently to get support from others, avoid obligations or give themselves more time to complete a task. And this is an important part of any signalling system, where the response to a particular signal will start to dictate how and why that signal is used.</span></p> <p><strong>People aren’t the only ones looking to benefit</strong></p> <p><span style="font-weight: 400;">Germs also use immune signals for their own gain.</span></p> <p><span style="font-weight: 400;">While some viruses hijack human immune responses such as coughs and sneezes to get passed on to new hosts, germs like SARS-COV-2 - which causes COVID-19 - can prevent our signalling to others that we are sick so it can spread without anyone realising.</span></p> <p><span style="font-weight: 400;">Viewing immunity as more than just a biological system could help us understand and even predict how particular infections will interact with a patient’s immune system, where </span><a href="https://theconversation.com/immune-response-might-be-more-about-signalling-to-others-that-you-need-help-and-less-about-protecting-your-body-160133"><span style="font-weight: 400;">future research</span></a><span style="font-weight: 400;"> could help us sort the immunity hijackers from other germs.</span></p>

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Six immunity and healthy ageing benefits of taking a daily arctic cod liver oil supplement

<div id="primary" class="contentAreaLeft"> <div class="Maincontent"> <p><strong>Cod liver oil has been used for centuries in Scandinavian societies to help people, young and old, stay healthy throughout the year.</strong></p> <p>Fresh cod liver oil is an excellent source of the omega-3 fatty acids EPA and DHA. Unlike most fish oil products, cod liver oil is unique in that it naturally contains a higher ratio of DHA to EPA, and typically delivers omega-3s in the triglyceride molecular form, the best form for their absorption by the body. Both EPA and DHA play vital roles in aspects of healthy ageing and immune function by influencing muscle and bone mass, mobility, energy, immune responses, and cognitive performance.</p> <p>Ensuring adequate intake of omega-3s with cod liver oil is an easy lifestyle change that can have a positive effect on many aspects of health. Here are some of the most notable omega-3 benefits of cod liver oil (a.k.a. CLO).</p> <p><strong>1. Omega-3s in CLO can support immune health via the gut</strong></p> <p>Having an overabundance of unhealthy gut bacteria can impair the immune system and accelerate the ageing process. Diet and lifestyle choices—including omega-3 consumption—are key factors for helping to establish a favourable environment for beneficial gut bacteria. Some studies have shown that increased consumption of omega-3s helps promote the growth of “good bacteria” in your gut, while other studies have shown a positive connection between adequate amounts of beneficial gut bacteria and a healthier immune response.</p> <p><strong>2. Omega-3 intake may influence muscle and bone strength</strong></p> <p>As we age, our immune system produces higher blood levels of inflammatory proteins that may impair muscle and bone health. Omega-3s supplements may support healthier blood levels of these age-associated proteins. Several studies report that people with higher dietary intake of omega-3s tend to have stronger muscles, increased exercise capacity, and denser bones. So consider a cod liver oil (especially one with vitamin D) for musculoskeletal health.</p> <p><strong>3. Omega-3s may help counter the effects of stress</strong></p> <p>Chronic stress increases the hormone cortisol, which can negatively impact immune health, especially if it remains elevated over a period of time. Some research studies have shown that omega-3 supplements may reduce the body’s production of cortisol. Furthermore, people who are “stressed out” tend to already have lower blood levels of the omega-3s EPA and DHA, potentially making it even more important for these individuals to consume supplemental omega-3s in order to keep from getting sick.</p> <p><strong>4. Omega-3s in CLO provide the building blocks for lasting, healthy skin</strong></p> <p>The skin is the largest organ in the body that also contains significant amounts of omega-3s. Due to years of exposure to ultraviolet light, toxins, and various irritants, the skin requires nutrients like omega-3s to help counter these stresses at the cellular level. The skin barrier is an important structure that protects the body and helps maintain a youthful appearance. Adequate intake of omega-3s supports skin cell functions, promotes the skin barrier, and increases the skin’s ability to retain water—a primary component of healthy skin. Because a portion of the omega-3s we consume eventually makes its way into the skin, these essential fats are vital for skin health.</p> <p><strong>5. Omega-3s in CLO support cardiovascular health</strong></p> <p>As we age, blood vessels stiffen, and blood pressure tends to increase, which places additional stress on the heart. Studies suggest that diets rich in omega-3s support healthy blood vessels, and several have reported that omega-3 supplements promote positive blood vessel health scores. Additionally, preliminary research suggests that omega-3 fatty acids may also help reduce oxidative stress within the blood vessels, promoting an optimal environment for the vasculature.</p> <p><strong>6. Higher intake of omega-3s is beneficial for eye moisture</strong></p> <p>People with higher dietary intake of omega-3s are less likely to experience symptoms of dry eyes, and they also tend to have healthier eye glands. Research has shown that omega-3 supplements can help stimulate the tear gland’s production of fatty oils on the eye surface. As ageing, and the use of digital devices like phones, tablets, and computers remain primary risk factors for eye dryness, consuming adequate amounts of omega-3s is a smart investment in long-term eye health.</p> <p><strong>Choosing the right cod liver oil</strong></p> <p>It’s a good idea to select a CLO product that’s from wild-caught sustainable cod, and that does not contain synthetic additives. Arctic Cod Liver Oil products are a good choice. Sustainable species like Arctic cod have several advantages. Arctic cod from Norway are often sourced using small boats owned and operated by independent cod fishermen, so demand for Arctic cod supports local fishing communities. Also, these boats leave and return daily which means they have a much shorter transport time from catch to processing than larger trawling vessels. This short time helps maximise fish oil freshness, and the efficacy of the omega-3 fats in Arctic Cod Liver Oil.</p> <p>By Warren Maginn, BHSc. (Nutr. Med.), GradCert. (Hum. Nutr.)<br /><em>Functional Nutritional Medicine Practitioner and Educator</em></p> <hr /> <p><strong>Nordic Naturals Arctic Cod Liver Oil™ is made from 100% wild Arctic cod. Unlike other “cod liver oils” on the market, no fish body oils or synthetic vitamins or additives are ever used.</strong></p> <p>Nordic Naturals award-winning Arctic Cod Liver Oil™ is made exclusively from wild Arctic cod, and is an ideal choice to help boost immune system health during the colder months. Vertically integrated from catch to finished product, Arctic Cod Liver Oil far surpasses the strict European Pharmacopoeia Standard for fish oil purity and freshness. Simply put it’s some of freshest cod liver oil in the world.</p> <p>Nordic Naturals Arctic Cod Liver oil recently won in the ‘Bone and Joint’ category of the Good Magazine Best of Natural Awards.</p> <p>Available from all good health stores. To find a store near you visit<span> </span><a href="http://www.therahealth.com.au/store-locator">http://www.therahealth.com.au/store-locator</a></p> <p><em>This article is sponsored content in conjunction with </em><a href="http://www.therahealth.com.au/"><em>Thera Health</em></a><em>.</em></p> </div> </div>

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Arctic cod liver oil: superstar for healthy ageing and immunity

<div id="primary" class="contentAreaLeft"> <div class="Maincontent"> <p><strong>We all need good nutrition for optimum wellbeing but this may be of even greater importance in our golden years.  Of the many nutrients that benefit healthy ageing, omega-3s are superstars since they are essential to the proper functioning of every cell in our bodies.</strong></p> <p>The main beneficial omega-3s, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are naturally highly concentrated in Arctic cod liver oil. The difference between Arctic cod liver oil and other fish oils is that Arctic cod liver oil generally contains 50% more DHA than EPA, whereas other fish oils are naturally higher in EPA than DHA.</p> <p>This ratio makes<span> </span><a rel="noopener noreferrer" href="http://www.therahealth.com.au/" target="_blank">Arctic cod liver oil</a><span> </span>stand out as a superfood for supporting systems that have an abundance of DHA such as the brain and eyes. In addition to this, Arctic cod liver oil contains a rare supply of naturally occurring vitamins A and D, providing further support for a range of body systems such as skin cell and immune support.</p> <p>Here are 6 ways that the nutrients found in Arctic Cod Liver Oil have been shown to support ageing &amp; immunity:</p> <p><strong>1. Heart health</strong></p> <p>Increasing levels of evidence have shown the beneficial impacts of dietary Omega 3’s against heart disease, and gaining sufficient omega-3 might be easiest done in the form of a cod liver oil supplement<span> </span><sup>(1)</sup>. Studies have indicated that dietary omega-3s appear to decrease the cardiovascular risk factors that lead to heart disease<span> </span><sup>(2,3)</sup>. This has been particularly obvious when cod liver oil supplementation has occurred in the Western diet. One particular study found that supplementing a typical Western diet with cod liver oil had positive effects on the heart health of study participants<span> </span><sup>(1)</sup>.</p> <p>This was likely due to the high concentration of omega-3’s contained in cod liver oil. As cardiovascular disease is a prominent health issue in Australia, Arctic cod liver oil may be an important addition to one’s diet in support of improving heart health<span> </span><sup>(4)</sup>.</p> <p><strong>2. Brain health</strong></p> <p>The brain tissue of humans is predominantly composed of lipids, which are made up of different fatty acids. DHA is the most abundant fatty acid in the brain. The levels of DHA in the brain increase during development and decrease with ageing. Further to this, DHA levels in the brain can be altered by dietary intake of omega-3s<span> </span><sup>(5)</sup>.</p> <p>A number of studies have suggested that low levels of DHA in the brain are linked to an increased risk of cognitive decline and dementia in older adults<span> </span><sup>(6)</sup>. Therefore, because of the rich profile of DHA in cod liver oil, supplementation of this particular fish oil may be specifically beneficial for the ageing population in support of brain health.</p> <p><strong>3. Bone strength</strong></p> <p>One of the main draw factors of cod liver oil is its naturally occurring vitamin D. While the most abundant method for increasing one’s vitamin D status is usually through sunlight exposure, sufficient and safe amounts of healthy sun exposure are increasingly difficult to achieve for many in the modern population.</p> <p>Therefore, cod liver oil supplementation may be a valuable alternative for supporting one’s required daily intake of vitamin D for optimal bone health. Osteoporosis is a bone disease characterised by decreased bone mass that occurs primarily in postmenopausal women<span> </span><sup>(7)</sup>. This disease places them at greater risk of fractures in their later life. Therefore, cod liver oil may be beneficial for supporting bone development and maintenance throughout life, and particularly in later life when the risk of bone fracture is increased.</p> <p><strong>4. Vision</strong></p> <p>Deteriorating eyesight is a common health problem in the ageing population. As with the brain, the eye is highly enriched with omega-3 fatty acids, with particularly high levels of DHA present in the retina of the eye<span> </span><sup>(8)</sup>. Therefore, DHA has an important functional role in the retina, primarily helping minimise the damage that is caused from the ongoing exposure to light throughout life<span> </span><sup>(12)</sup>.</p> <p>Therefore, people over the age of 50 are recommended a regular intake of marine fish or a food supplement that has high concentrations of DHA, such as cod liver oil, to support their eye health<span> </span><sup>(12)</sup>. In addition to this, cod liver oil is appealing because it is a good source of naturally occurring vitamin A in its most ‘active’ form, which may support individuals who have problems with night vision.</p> <p><strong>5. Skin care</strong></p> <p>Human skin plays a pivotal role in the feeling of wellbeing and physical attractiveness in an individual<span> </span><sup>(14)</sup>. Our skin is continuously exposed to internal and external influences that may alter its condition. As a result, we may experience inflammation, immune dysfunction, skin disorders, and ultimately ageing.</p> <p>The functioning and attractiveness of the skin are dependent on nutrition, as evidenced by the characteristic skin lesions that often occur from particular deficiencies in the diet.<sup><span> </span>(14)</sup><span> </span>Dietary supplementation with specific vitamins, minerals, or essential fatty acids will therefore support skin care in these situations<span> </span><sup>(15)</sup>. Many reports have suggested that the intake of omega-3s, (EPA and DHA), may provide considerable health benefits in relation to inflammatory diseases that have the potential to cause rashes, lesions or other disorders to the skin. One study found that a relatively low supplemented dose of EPA and DHA within a 4-week period was protective against UV radiation<span> </span><sup>(16)</sup>. Therefore, cod liver oil supplementation may be recommended to help and support skin care in later life.</p> <p><strong>6. Immune system</strong></p> <p>Many studies have found that the anti-inflammatory profile of cod liver oil supports the immune response of an individual. Further to this, the effect of omega-3 dietary supplementation has been shown to improve clinical variables of disease activity<span> </span><sup>(17)</sup>. One study found that cod liver oil supplementation for individuals with rheumatoid arthritis allowed these patients to decrease their NSAID (non-steroidal anti-inflammatory drugs) intake, thus improving gastrointestinal and cardiovascular health without any worsening of disease activity<span> </span><sup>(17)</sup>.</p> <p>Another study produced results that suggested a protective effect of cod liver oil supplementation against type 1 diabetes<span> </span><sup>(18)</sup>. Numerous changes occur in the immune system with advancing age, probably contributing to a decreased immune response<span> </span><sup>(20)</sup>.</p> <p>Looking at these amazing benefits for multiple body systems, you can see why Arctic cod liver oil is a superstar for immune support and healthy ageing.</p> <p>Nordic Naturals Arctic Cod Liver Oil™ is made from 100% wild Arctic cod. Unlike other “cod liver oils” on the market, no fish body oils or synthetic vitamins or additives are ever used.</p> <p>Nordic Naturals award-winning Arctic Cod Liver Oil™ is made exclusively from wild Arctic cod, and is an ideal choice to help boost immune system health during the colder months. Vertically integrated from catch to finished product, Arctic Cod Liver Oil far surpasses the strict European Pharmacopoeia Standard for fish oil purity and freshness. Simply put it’s some of freshest cod liver oil in the world.</p> <p>Nordic Naturals Arctic Cod Liver oil recently won in the ‘Bone and Joint’ category of the Good Magazine Best of Natural Awards.</p> <p>Available from all good health stores. To find a store near you visit<span> </span><a rel="noopener noreferrer" href="http://www.therahealth.com.au/store-locator" target="_blank">http://www.therahealth.com.au/store-locator</a></p> <p><em>This article is sponsored content in conjunction with<span> </span><a rel="noopener noreferrer" href="http://www.therahealth.com.au/" target="_blank">Thera Health</a>.</em></p> <p><em><sup><strong>REFERENCES</strong></sup></em></p> <ol> <li><em>Lorenz R, Spengler U, Fischer S, Duhm J and Weber PC. Platelet Function, Thromboxane Formation and Blood Pressure Control During Supplementation of the Western Diet with Cod Liver Oil. Circulation 1983;67:504-511.</em></li> <li><em>Simopoulos AP. Omega-3 fatty acids in health and disease and in growth and development. Am J Clin Nutr 1991;54:438-463.</em></li> <li><em>Hu FB, Bronner L and Willett WC. Fish and Omega-3 Fatty Acid Intake and Risk of Coronary Heart Disease in Women. JAMA 2002;287)14):1815-21.</em></li> <li><em>Heart Foundation. 2014. Data and statistics. Available at:<a href="http://www.heartfoundation.org.au/information-for-professionals/data-and-statistics/Pages/default.aspx">http://www.heartfoundation.org.au/information-for-professionals/data-and-statistics/Pages/default.aspx</a>. [Accessed 26 March 14].</em></li> <li><em>Innis SM. Dietary omega 3 fatty acids and the developing brain. Brain Res 2008;doi 10.1016.</em></li> <li><em>Sydenham E, Dangour AD and Lim W-S. Omega 3 fatty acid for the prevention of cognitive decline and dementia. Sao Paulo Med J 2012;130(6):419.</em></li> <li><em>Rajakumar K. Vitamin D, Cod-Liver Oil, Sunlight, and Rickets: A Historical Perspective. Pediatrics 2003;112;e132.</em></li> <li><em>Hodge W, Barnes D, Schachter HM et al. Effects of Omega-3 Fatty Acids on Eye Health. AHRQ 2005;117:12.</em></li> <li><em>James MJ, Gibson RA and Cleland LG. Dietary polyunsaturated fatty acids and inflammatory mediator production. Am J Clin Nutr 2000;71.</em></li> <li><em>Rodriguez de Turco EB, Gordon WC and Bazan NG. Rapid and selective uptake, metabolism, and cellular distribution of docosahexenoic acid among rod and cone photoreceptor cells in the frog retina. J Neurosci 1991;11(11):3667-78.</em></li> <li><em>Vingerling JR, Dielemans I, Bots ML et al. Age-related macular degeneration is associated with atherosclerosis. The Rotterdam Study. Am J Epidemiol 1995;142(4):404-9.</em></li> <li><em>Bryhn M. 2007. Can Omega-3 Fatty Acids Prevent Blindness? Available at:<span> </span><a href="http://www.parisan.de/fileadmin/parisan/user_upload/EPAX_-_Eye_Health.pdf">http://www.parisan.de/fileadmin/parisan/user_upload/EPAX_-_Eye_Health.pdf</a><span> </span>(Accessed 26 March 2014).</em></li> <li><em>Neuringer M. Infant vision and retinal function in studies of dietary long-chained polyunsaturated fatty acids. Am J Clin Nutr 2000;71:256-267.</em></li> <li><em>Boelsma E, Hendriks HFJ and Roza L. Nutritional skin care: health effects of micronutrients and fatty acids. Am J Clin Nutr 2001;73:853-64.</em></li> <li><em>Roe DA. Current etiologies and cutaneous signs of vitamin deficiencies. Roe Da, ed. Nutrition and the skin. Contemporary issues in clinical nutrition. New York: Alan R Liss Inc, 1986;81-98.</em></li> <li><em>Orengo IF, Black HS and Wolf JE. Influence of fish oil supplementation on the minimal erythema dose in humans. Arch Dermatol Res 1992;284:219-21.</em></li> <li><em>Galarraga B, Ho M and Youssef HM. Cod liver oil (n-3 fatty acids) as a non-steroidal anti-inflammatory drug sparing agent in rheumatoid arthritis. Rheumatology 2008;47:665-669.</em></li> <li><em>Stene LC, Ulriksen J, Magnus P and Joner G. Use of cod liver oil during pregnancy associated with lower risk of Type 1 diabetes in the offspring. Diabetologia 2000;43:1093-98.</em></li> <li><em>Stene LC, Joner G and the Norwegian Childhood Diabetes Study Group. Use of cod liver oil during the first year of life is associated with lower risk of childhood-onset type 1 diabetes: a large, population-based, case-control study. Am J Clin Nutr 2003;78:1128-34.</em></li> <li><em>Immunity &amp; Ageing. 2014. About Immunity &amp; Ageing. Available at<span> </span><a href="http://www.immunityageing.com/about">http://www.immunityageing.com/about</a><span> </span>(Accessed 27 March 2014).</em></li> </ol> </div> </div>

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5 life lessons from your immune system

<p>Scientists love analogies. We use them continually to communicate our scientific approaches and discoveries.</p> <p>As an immunologist, it strikes me that many of our recurring analogies for a healthy, functioning immune system promote excellent behaviour traits. In this regard, we should all aim to be a little more like the cells of our immune system and emulate these characteristics in our lives and workplaces.</p> <p>Here are five life lessons from your immune system.</p> <p><strong>1. Build diverse and collaborative teams</strong></p> <p>Our adaptive immune system works in a very specific way to detect and eradicate infections and cancer. To function, it relies on effective team work.</p> <p>At the centre of this immune system team sits dendritic cells. These are the sentinels and leaders of the immune system – akin to coaches, CEOs and directors.</p> <p>They have usually travelled widely and have a lot of “life experience”. For a dendritic cell, this means they have detected a pathogen in the organs of the body. Perhaps they’ve come into contact with influenza virus in the lung, or encountered dengue fever virus in the skin following a mosquito bite.</p> <p>After such an experience, dendritic cells make their way to their local lymph nodes – organs structured to facilitate immune cell collaboration and teamwork.</p> <p>Here, like the best leaders, dendritic cells share their life experiences and provide vision and direction for their team (multiple other cell types). This gets the immune cell team activated and working together towards a shared goal – the eradication of the pathogen in question.</p> <p>The most important aspect of the dendritic cell strategy is knowing <a href="https://www.pnas.org/content/101/46/16385">the strength of combined diverse expertise</a>. It is essential that immune team members come from diverse backgrounds to get the best results.</p> <p>To do this, dendritic cells secrete small molecules known as chemokines. Chemokines facilitate good conversations between different types of immune cells, helping dendritic cells discuss their plans with the team. In immunology, we call this “recruitment”.</p> <p>Much <a href="https://www.nature.com/articles/s41467-018-07634-8">like our workplaces</a>, diversity is key here. It’s fair to say, if dendritic cells only recruited more dendritic cells, our immune system would completely fail its job. Dendritic cells instead hire T cells (among others) and share the critical knowledge and strategy to steer effective action of immune cells.</p> <p>T cells can then pass these plans down the line – either preparing themselves to act directly on the pathogen, or working alongside other cell types, such as B cells that make protective antibodies.</p> <p>In this way, dendritic cells establish a rich and diverse team that works together to clear infections or cancer.</p> <p><strong>2. Learn through positive and negative feedback</strong></p> <p>Immune cells are excellent students.</p> <p>During development, T cells mature in a way that depends on both positive and negative feedback. This occurs in the thymus, an organ found in the front of your chest and whose function was first discovered by Australian scientist <a href="https://www.wehi.edu.au/about-history/notable-scientists/professor-jacques-miller">Jacques Miller</a> (awarded the <a href="http://www.japanprize.jp/en/prize_prof_2018_miller.html">2018 Japan Prize</a> for his discoveries).</p> <p>As they mature, T cells are exposed to a process of trial and error, and take on board criticism and advice in equal measure, to ensure they are “trained” to respond appropriately to what they “see” (for example, molecules from your own body, or from a foreign pathogen) when they leave the thymus.</p> <p>Importantly, this process is balanced, and T cells must receive both positive and negative feedback to mature appropriately – too much of either on its own is not enough.</p> <p>In the diverse team of the immune system, cells can be both the student and the teacher. This occurs during immune responses with intense cross-talk between dendritic cells, T cells and B cells.</p> <p>In this supportive environment, multiple rounds of feedback allow B cells to gain a tighter grip on infections, tailoring antibodies specifically towards each pathogen.</p> <p>The result of this feedback is so powerful, it can divert cells away from acting against your own body, instead converting them into <a href="https://www.ncbi.nlm.nih.gov/pubmed/29650674">active participants of the immune system team</a>.</p> <p>Developing avenues that promote constructive feedback offers potential to correct autoimmune disorders.</p> <p><strong>3. A unique response for each situation</strong></p> <p>Our immune system knows that context is important – it doesn’t rely on a “one-size–fits-all” approach to resolve all infections.</p> <p>This allows the cells of our immune system to perfectly respond to different types of pathogens: such as viruses, fungi, bacteria and helminths (worms).</p> <p>In these different scenarios, even though the team members contributing to the response are the same (or similar), our immune system displays emotional intelligence and utilises different tools and strategies depending on the different situations, or pathogens, it encounters.</p> <p>Importantly, our immune system needs to carefully control attack responses to get rid of danger. Being too heavy handed leaves us with collateral tissue damage, such as is seen allergy and asthma. Conversely, weak responses lead to immunodeficiencies, chronic infection or cancer.</p> <p>A major research aim for people working in immunology is to learn how to harness balanced and tailored immune responses for therapeutic benefit.</p> <p><strong>4. Focus on work/life balance</strong></p> <p>When we are overworked and poorly rested, we don’t function at our peak. The same is true for our immune cells.</p> <p>An overworked immune cell is commonly referred to as being “chronically exhausted”. In this state, T cells are no longer effective at attacking tumour or virus-infected cells. They are lethargic and inefficient, much like us when we overdo it.</p> <p>For T cells, this switch to exhaustion helps ensure a balanced response and avoids collateral damage. However, viruses and cancers exploit this weakness in immune responses by deliberately promoting exhaustion.</p> <p>The rapidly advancing field of immunotherapy has tackled this limitation in our immune system head-on to create new cancer therapeutics. These therapies release cells of their exhaustion, refresh them, so they become effective once more.</p> <p>This therapeutic avenue (called “<a href="https://theconversation.com/2018-nobel-prize-in-physiology-or-medicine-a-turning-point-in-the-war-on-cancer-104191">immune checkpoint inhibition</a>”) is like a self-care day spa for your T cells. It revives them, renewing their determination and efficiency.</p> <p>This has revolutionised the way cancer is treated, leading to the award of the <a href="https://www.nobelprize.org/prizes/medicine/2018/press-release/">2018 Nobel prize in Medicine</a> to two of its pioneers, James P. Allison and Tasuku Honjo.</p> <p><strong>5. Learn from life experiences</strong></p> <p>The cornerstone of our adaptive immune system is the ability to remember our past infections. In doing so, it can respond faster and in a more targeted manner when we encounter the same pathogen multiple times.</p> <p>Quite literally, if it doesn’t kill you, it makes your immune system stronger.</p> <p>Vaccines exploit this <em>modus operandi</em>, providing immune cells with the memories without the risk of infection.</p> <p>Work still remains to identify the pathways that optimise formation of memory cells that drive this response. Researchers aim to discover which memories are the most efficient, and how to make them target particularly recalcitrant infections, such as malaria, HIV-AIDS and seasonal influenza.</p> <p>While life might not have the shortcuts provided by vaccines, certainly taking time to reflect and learn after challenges can allow us to find better, faster solutions to future problems.</p> <p><span><a href="https://theconversation.com/profiles/joanna-groom-550055"><em>Joanna Groom</em></a><em>, Laboratory Head, <a href="https://theconversation.com/institutions/walter-and-eliza-hall-institute-822">Walter and Eliza Hall Institute</a></em></span></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/five-life-lessons-from-your-immune-system-103425">original article</a>.</em></p>

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Are you able to become immune to coronavirus?

<p>As the number of people infected with coronavirus is more than 450,000, scientists are currently wrestling with questions that are left after people recover from the virus. Do people survive the infection become immune to the virus?</p> <p>The answer is luckily, yes but there are some significant unknowns with that as well.</p> <p>As growing immunity in the community is also the way the pandemic ends, scientists are working overtime to figure out what these significant unknowns are and how they’ll impact the larger community.</p> <p>It is currently unclear how long people who have been infected and beaten the virus are left with an immunity against it, with some medical professionals believing that there may be an immunity of at least one to two years.</p> <p>Florian Krammer, a microbiologist at the Icahn School of Medicine at Mount Sinai in New York, says that even if people became reinfected, the second bout of coronavirus would likely be much milder than the first.</p> <p>“You probably would make a good immune response before you even become symptomatic again and might really blunt the course of the disease,” Dr. Krammer said to<span> </span><em><a rel="noopener noreferrer" href="https://www.nytimes.com/2020/03/25/health/coronavirus-immunity-antibodies.html" target="_blank">The New York Times</a>.</em></p> <p>Antibody tests are being used in Singapore, China and a handful of other countries. However, they are just making their way into the West. Antibody tests are the quickest way to assess immunity, as it’s a blood test that looks for protective antibodies in the blood of people who have recovered.</p> <p>“No matter who makes them, as long as they’re reliable, that’s a super nice tool,” Dr. Krammer said. Because this is a new coronavirus, the test should deliver “basically, a yes or no answer, like an H.I.V. test — you can figure out who was exposed and who wasn’t.”</p> <p>Dr Krammer’s tests pick up an antibody response as early as three days after symptoms emerge, but given people might not show symptoms for as long as 14 days after infection, it’s too late for the test to be useful as a diagnostic tool.</p> <p>Ultimately, it’s only with the tests that scientists are using that they will be able to say when enough of the population has become infected and therefore has made people immune.</p>

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"Herd immunity" response plan sparks incredulous response

<p><span>The United Kingdom’s approach to COVID-19 has sparked widespread backlash as scientists urged the government to introduce tougher measures to deal with the pandemic.</span></p> <p><span>More than 220 scientists have signed an open letter condemning the government’s chief scientific adviser Sir Patrick Vallance, who said on Friday the spread of the infection could be managed to make the population immune.</span></p> <p><span>According to Sir Patrick, about 60 per cent of the population would need to get ill to reach “herd immunity”. The idea means at-risk individuals would be protected from infection because the people around them would be resistant to the disease.</span></p> <p><span>“Our aim is to try and reduce the peak, broaden the peak, not suppress it completely,” he said.</span></p> <p><span>However, the scientists argued in the letter such option is not “viable” and will risk “many more lives than necessary”.</span></p> <p><span>Dr William Hanage, professor of the evolution and epidemiology of infectious disease at Harvard T. H. Chan School of Public Health, said he thought the policy would overwhelm the healthcare system and put high-risk population in danger.</span></p> <p><span>Herd immunity only works to protect vulnerable individuals if most people in the population are vaccinated, according to <a href="https://vk.ovg.ox.ac.uk/vk/herd-immunity">Oxford Vaccine Group</a>.</span></p> <p><span>“We talk about vaccines generating herd immunity, so why is this different? Because this is not a vaccine,” Dr Hanage wrote on <em><a href="https://www.theguardian.com/commentisfree/2020/mar/15/epidemiologist-britain-herd-immunity-coronavirus-covid-19">The Guardian</a></em>. </span></p> <p><span>“This is an actual pandemic that will make a very large number of people sick, and some of them will die.</span></p> <p><span>“This virus is capable of shutting down countries. You should not want to be the next after Wuhan, Iran, Italy or Spain. In those places, the healthcare systems have broken down.”</span></p> <p><span>University of Auckland associate professor Helen Petousis-Harris said a herd immunity strategy means “throwing people under the train”.</span></p> <p><span>“When you have that proportion of the community affected, you can probably calculate how many people will be dead,” she told <em><a href="https://www.stuff.co.nz/national/health/coronavirus/120326939/nz-scientists-horrified-at-herd-immunity-strategy">Stuff.co.nz</a></em>. “When you have that overwhelming explosion of cases, your health system is overwhelmed and your mortality rate goes up.”</span></p> <p><span>Following the criticism, the country’s Prime Minister Boris Johnson on Monday advised people to avoid non-essential travel and contact with others. He also asked households where someone was displaying symptoms to self-isolate for 14 days.</span></p> <p><span>At the time of writing, the UK has not introduced mandatory self-isolation measures for international arrivals.</span></p>

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What is herd immunity and how many people need to be vaccinated to protect a community?

<p>The term herd immunity comes from the observation of how a herd of buffalo forms a circle, with the strong on the outside protecting the weaker and more vulnerable on the inside.</p> <p>This is similar to how herd immunity works in preventing the spread of infectious diseases. Those who are strong enough to get vaccinated directly protect themselves from infection. They also indirectly shield vulnerable people who cannot be vaccinated.</p> <p>There are various reasons a person may not be able to be successfully vaccinated. People undergoing cancer treatment, and whose immune systems are compromised, for instance, are impaired in their ability to develop protective immunity from all vaccines. Often, people who can’t be vaccinated are susceptible to the most serious consequences from being infected.</p> <p>Another vulnerable group are babies. <a href="https://www.health.gov.au/health-topics/flu-influenza">Infants under six months of age</a> are susceptible to serious complications from influenza. Yet they can’t be given the flu vaccine as their immune systems are not strong enough.</p> <p><strong>How does herd immunity work?</strong></p> <p>For a contagious disease to spread, an infectious agent needs to find susceptible (non-immune) people to infect. If it can’t, the chain of infection is interrupted and the amount of disease in the population reduces.</p> <p>Another way of thinking about it is that the disease needs susceptible victims to survive in the population. Without these, it effectively starves and dies out.</p> <p>What level of coverage provides herd immunity?</p> <p>How many people need to be vaccinated to achieve herd immunity varies from disease to disease.</p> <p>Measles can be transmitted through coughing and sneezing and the virus causing measles can survive outside the body for <a href="https://www.cdc.gov/measles/transmission.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fmeasles%2Fabout%2Ftransmission.html">up to two hours</a>. So it’s possible to catch measles just by being in the same room as someone who is ill if you touch a surface they’ve coughed or sneezed on.</p> <p>In contrast, Ebola can only be spread by direct contact with infected secretions (blood, faeces or vomit) and therefore requires close contact with an ill person. This makes it much less spreadable.</p> <p>We can determine how contagious a disease is by tracking its spread throughout a population. In doing so, we can attribute each disease a reproductive number denoted by the symbol Ro. The bigger the Ro the more easily the disease is spread throughout the population.</p> <p>If everyone who has a disease on average infects two people, the Ro for that disease is 2. This means the disease, relatively speaking, is not particularly contagious. However, if everyone who has a disease infects ten people on average, it would have an Ro of 10, which means it’s a much more contagious disease.</p> <p>We can use the Ro for a disease to calculate the herd immunity threshold, which is the minimum percentage of people in the population that would need to be vaccinated to ensure a disease does not persist in the population. The more contagious a disease, the higher the threshold.</p> <p><strong>Herd immunity threshold</strong></p> <p>Measles is one of the most infectious diseases to affect humans with an <a href="https://www.who.int/immunization/newsroom/multimedia/Chapter_1.pdf?ua=1">Ro of 12-18</a>. To achieve herd immunity to measles in a population we need <a href="https://www.who.int/immunization/sage/meetings/2017/october/2._target_immunity_levels_FUNK.pdf">92-95%</a> of the population to be vaccinated.</p> <p>Current data indicates full vaccine coverage for five year olds in Australia is sitting at <a href="https://www.health.gov.au/health-topics/immunisation/childhood-immunisation-coverage">around the 95% level</a>. However, vaccination rates in <a href="https://www.health.gov.au/sites/default/files/2018-phn-childhood-immunisation-coverage-data-december-2018-annualised-data-all-children.pdf">some communities</a> have fallen below ideal levels, making them susceptible to measles outbreaks.</p> <p>The overwhelming success of measles vaccinations means many people have no memory of what this disease looks like, and this has resulted in its effects being underestimated. Measles can cause <a href="https://www.ncbi.nlm.nih.gov/pubmed/14998696">blindness</a> and <a href="https://www.hopkinsmedicine.org/neurology_neurosurgery/centers_clinics/encephalitis/acute_encephalitis.html">acute encephalitis</a> (inflammation of the brain), which can result in permanent brain damage.</p> <p>Herd immunity, or community immunity, as it’s sometimes called, is a powerful public health tool. By ensuring those who can be vaccinated do get vaccinated we can achieve herd immunity and prevent the illness and suffering that comes from the spread of infectious diseases.</p> <p><em>Written by Hassan Vally. Republished with permission of </em><a href="https://theconversation.com/what-is-herd-immunity-and-how-many-people-need-to-be-vaccinated-to-protect-a-community-116355"><em>The Conversation</em></a><em>.</em></p>

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