{"id":13204,"date":"2024-12-10T10:00:00","date_gmt":"2024-12-10T10:00:00","guid":{"rendered":"https:\/\/modernsciences.org\/staging\/4414\/?p=13204"},"modified":"2024-11-29T07:15:56","modified_gmt":"2024-11-29T07:15:56","slug":"long-covid-driven-long-infection-science-says-december-2024","status":"publish","type":"post","link":"https:\/\/modernsciences.org\/staging\/4414\/long-covid-driven-long-infection-science-says-december-2024\/","title":{"rendered":"Long COVID appears to be driven by \u2018long infection\u2019. Here\u2019s what the science says"},"content":{"rendered":"\n
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\n \n Alexander Grey\/Unsplash<\/a><\/span>\n <\/figcaption>\n <\/figure>\n\n Brendan Crabb<\/a>, Burnet Institute<\/a><\/em>; Gabriela Khoury<\/a>, Burnet Institute<\/a><\/em>, and Michelle Scoullar<\/a>, Burnet Institute<\/a><\/em><\/span>\n\n

Around 5\u201310%<\/a> of people with COVID infections go on to experience long COVID, with symptoms lasting three months or more. <\/p>\n\n

Researchers have proposed several biological mechanisms<\/a> to explain<\/a> long COVID. However, in a perspective article<\/a> published in the latest Medical Journal of Australia, we argue that much, if not all, long COVID appears to be driven by the virus itself persisting in the body. <\/p>\n\n

Since relatively early in the pandemic, there has been a recognition<\/a> that in some people, SARS-CoV-2 \u2013 or at least remnants of the virus \u2013 could stay in various tissues and organs for extended periods. This theory is known as \u201cviral persistence\u201d. <\/p>\n\n

While the long-term presence of residual viral fragments in some people\u2019s bodies is now well established, what remains less certain is whether live virus itself, not just old bits of virus, is lingering \u2013 and if so, whether this is what causes long COVID. This distinction is crucial because live virus can be targeted by specific antiviral approaches in ways that \u201cdead\u201d viral fragments cannot.<\/p>\n\n

Viral persistence has two significant implications<\/a>:<\/p>\n\n

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  1. when it occurs in some highly immunocompromised people, it is thought to be the source of new and substantially different-looking variants, such as JN.1<\/a> <\/p><\/li>\n

  2. it has the potential to continue to cause symptoms in many people in the wider population long beyond the acute illness. In other words, long COVID could be caused by a long infection.<\/p><\/li>\n<\/ol>\n\n

    What does the research say?<\/h2>\n\n

    While there remains no single study that confirms that persistent virus is the cause of long COVID, collectively several recent key papers make a compelling case. <\/p>\n\n

    In February, a study in Nature found<\/a> a high number of people with mild COVID symptoms had extended periods of shedding the genetic material of the virus, so-called viral RNA, from their respiratory tract. Those with persistent shedding of this viral RNA \u2013 which almost certainly represents the presence of live virus \u2013 were at higher risk of long COVID.<\/p>\n\n

    Other key papers detected replicating viral RNA<\/a> and proteins<\/a> in blood fluid of patients years after their initial infection, a sign that the virus is likely replicating for long periods in some hidden reservoirs in the body, perhaps including blood cells. <\/p>\n\n

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    \n The virus could be hiding out, causing symptoms of long COVID.<\/span>\n tonecgi\/Shutterstock<\/a><\/span>\n <\/figcaption>\n <\/figure>\n\n

    Another study detected<\/a> viral RNA in ten different tissue sites and blood samples 1\u20134 months after acute infection. This study found the risk of long COVID (measured four months following infection) was higher in those with persistently positive viral RNA. <\/p>\n\n

    The same study<\/a> also gave clues about where in the body the persisting virus resides. The gastrointestinal tract is one site of considerable interest as a long-term viral hideout. <\/p>\n\n

    Earlier this week, further evidence<\/a> of persistent virus increasing likelihood of long COVID has been published as part of the RECOVER initiative<\/a>, a collaborative research project that aims to address the impacts of long COVID. <\/p>\n\n

    However, formal proof that virus capable of replicating can last for years in the body remains elusive. This is because isolating the live virus from reservoirs inside the body where the virus \u201chides\u201d is technically challenging. <\/p>\n\n

    In its absence, we and other<\/a> scientists<\/a> argue the cumulative evidence is now sufficiently compelling to galvanise action.<\/p>\n\n

    What needs to happen next?<\/h2>\n\n

    The obvious response to this is to fast-track trials of known antivirals<\/a> for prevention and cure of long COVID. <\/p>\n\n

    This should include more left-field therapies such as the diabetes drug metformin. This has possible dual benefits in the context of long COVID:<\/p>\n\n