By\u00a0Katie Camero, NBC News<\/p>\n\n\n\n
Why do some people develop disabling chronic conditions after the initial viral infection?<\/p>\n\n\n\n
<\/a><\/a><\/a>The struggles of living with long Covid five years after the start of the pandemic<\/a><\/a><\/p>\n\n\n\n When her school closed down in March 2020, Chim\u00e9re Sweeney, an English teacher in Baltimore, thought she\u2019d return to her students once the U.S. got a handle on the new SARS-CoV-2 virus. But \u201clife had a different plan\u201d when she got Covid shortly after \u2014 and then never recovered, she said.<\/p>\n\n\n\n At first, Sweeney developed only muscle aches. By the second week, she started having panic attacks, blurry vision, constipation and partial hearing loss. Half of her face would freeze \u201clike concrete.\u201d She forgot phone numbers and addresses and she developed a stutter. Within a month after getting infected, she lost 30 pounds. <\/p>\n\n\n\n \u201cI was told that after two weeks I would be better,\u201d Sweeney, now 42, said. \u201cBut my two weeks never came.\u201d<\/p>\n\n\n\n Almost five years later, she\u2019s still struggling with severe whole body pain, sleeplessness, depression, painful rashes and boils, uncontrollable urination, short-term memory loss, and irregular periods. <\/p>\n\n\n\n \u201cI went from being a healthy 37-year-old woman who may have had to pop an allergy pill every now and again, to taking over 10 to 12 medications per day to control almost every system in my body,\u201d Sweeney said.<\/p>\n\n\n\n Since the World Health Organization characterized Covid as a pandemic on March 11, 2020, scientists don\u2019t fully understand why some people develop disabling chronic conditions after the initial viral infection. The U.S. may be coming through the first post-pandemic winter without a major surge in cases, but each infection carries a risk of developing long Covid. Some scientists are calling for new types of clinical trials to be designed for the most debilitated long Covid sufferers. <\/p>\n\n\n\n Long Covid is known to cause\u00a0over 200 different symptoms<\/a>\u00a0in nearly a dozen organ systems, including those of the heart, lungs, kidneys, brain, eyes and skin, but there\u2019s no approved test for it or recommended treatment.\u00a0Research shows long Covid<\/a>\u00a0is more common in middle-aged people, particularly women and those with weakened immune systems, but anyone who catches the virus can get it.\u00a0<\/p>\n\n\n\n The Centers for Disease Control and Prevention has estimated that 1 in 20 adults in the U.S., or about 14 million, are living with long Covid<\/a>. Other data shows that up to 5.8 million children<\/a> may be affected by the condition as well. However, experts say these numbers are likely underestimated because there\u2019s no official surveillance system in place.<\/p>\n\n\n\n A $1 billion research initiative called RECOVER<\/a> launched by the National Institutes of Health to find the causes of long Covid, as well as potential treatments, has fallen short on its promises<\/a>, scientists and patient advocates say. <\/p>\n\n\n\n Meanwhile, experts fear that the Trump administration\u2019s extreme cuts in federal spending may undermine long Covid research efforts<\/a>, which could further delay the discovery of therapies. Just last month, President Donald Trump terminated the Health and Human Services Secretary\u2019s Advisory Committee on Long COVID<\/a>. <\/p>\n\n\n\n Dr. W. Michael Brode, medical director of UT Health Austin\u2019s Post-COVID-19 Program<\/a> in Texas, said, \u201cWe\u2019re building the boat while we\u2019re at sea, trying to figure it out together [with patients] \u2026 but we absolutely need to build on the progress we\u2019ve already made.\u201d <\/p>\n\n\n\n \u201cWe have not delivered the answers commensurate with the public health crisis we\u2019re facing,\u201d he said.<\/p>\n\n\n\n SARS-CoV-2, which causes Covid, isn\u2019t the only virus that causes lingering symptoms. Another condition called myalgic encephalomyelitis\/chronic fatigue syndrome (ME\/CFS), which shares many similarities with long Covid, is thought to be triggered by infections<\/a> with the Epstein-Barr, influenza and varicella-zoster viruses, among others. <\/p>\n\n\n\n Covid is unique because it seems more likely to cause chronic illness than other pathogens, Brode said. Why it may lead to long-lasting symptoms is as yet undetermined. Experts have so far landed on several theories. <\/p>\n\n\n\n One idea is that remnants of the virus hide in different tissues<\/a> after an infection subsides, Brode said. These viral particles continue to multiply or stimulate the immune system in ways that trigger long Covid symptoms. <\/p>\n\n\n\n Another potential cause involves the reactivation of other viruses<\/a>, such as EBV and HIV, that have been sitting in a dormant state in people\u2019s bodies. <\/p>\n\n\n\n It\u2019s also possible that Covid tricks the immune system into producing antibodies that attack a person\u2019s own healthy organs and tissues, said Dr. Igor Koralnik, co-director of Northwestern Medicine\u2019s Comprehensive COVID-19 Center.\u00a0<\/a><\/a><\/a><\/p>\n\n\n\n Some evidence shows that Covid affects the inner lining of the blood vessels<\/a>, which can lead to the formation of tiny clots and help explain symptoms like irregular heartbeats and heart failure that some long Covid patients experience, Koralnik said. <\/p>\n\n\n\n It\u2019s unclear whether one or a combination of these factors causes long Covid, experts say. But evidence suggests that they\u2019re all associated with increased inflammation in the body, Koralnik said, which is why your risk of long Covid increases with each Covid infection<\/a>. <\/p>\n\n\n\n \u201cIt\u2019s like a river going over a dam,\u201d Koralnik said. \u201cThe more episodes of Covid, the more the river level goes up to the point it overflows and there\u2019s a flooding of long Covid symptoms.\u201d <\/p>\n\n\n\n Diagnosing long Covid can be complicated.<\/p>\n\n\n\n Although we have diagnostic tools to confirm symptoms of long Covid, such as MRI scans for heart abnormalities, there\u2019s no test that can diagnose the condition<\/a> or distinguish it from similar illnesses, the CDC says. <\/p>\n\n\n\n As a result, people have to step away from work, school or other responsibilities to endure dozens of laboratory tests and scans that are not only expensive, but also stressful and time-consuming. It\u2019s an extensive process of elimination that prevents people from getting the help they need, Brode said. <\/p>\n\n\n\n The challenge now is finding one or more biomarkers \u2014 genes, proteins or other substances associated with a specific condition \u2014 that can help diagnose long Covid. <\/p>\n\n\n\n A RECOVER study<\/a> published last year found that routine lab tests, including 25 standard blood and urine exams, found few differences in biomarkers between people with and without prior Covid infection. The researchers concluded that these tests may not be useful in diagnosing long Covid. <\/p>\n\n\n\n Koralnik and his team recently discovered that people with long Covid have decreased blood flow in the small blood vessels in their retina, the light-sensitive layer behind the eye. This reduced flow is thought to decrease blood circulation in and around the brain, Koralnik said, which might \u201cpoison\u201d tiny organelles called mitochondria that convert oxygen into energy. <\/p>\n\n\n\n This theory can explain why many people with long Covid experience cognitive issues, fatigue and exercise intolerance, Koralnik said. Overall, the findings, published in February in the Journal of Imaging, suggest the retina could be a long Covid biomarker<\/a>. <\/p>\n\n\n\n Other research suggests promising biomarkers might exist in the gut and immune system, but Brode noted that these early findings are based on small groups of people and should be considered with a grain of salt. <\/p>\n\n\n\n As helpful as a diagnostic test would be for people with lingering symptoms, some experts say the lack of one shouldn\u2019t slow scientists down in their search for long Covid treatments. <\/p>\n\n\n\n Julia Moore Vogel, senior program director with Scripps Research and contributor to the Patient-Led Research Collaborative<\/a> for long Covid, said other conditions like migraine don\u2019t have reliable biomarkers or tests to confirm diagnoses, yet several drugs are approved<\/a> to treat it. <\/p>\n\n\n\n \u201cI think we\u2019ll get there,\u201d said Vogel, who was a long-distance runner before developing long Covid in 2020 and now needs a wheelchair. \u201cBut I don\u2019t personally feel like that should hold anything back.\u201d<\/p>\n\n\n\n The Food and Drug Administration hasn\u2019t approved any treatments specifically for long Covid. Experts aren\u2019t sure we\u2019ll get any soon.<\/p>\n\n\n\n \u201cWhen I first got sick, I was like, OK, I just have to survive three to five years and I think there will be, at least, decent symptom management trial data so that we have options. But we\u2019ve made almost no progress on treatments,\u201d Vogel said. \u201cThere are now studies starting that are promising, but it\u2019s nowhere near the volume it should be given the burden of disease.\u201d<\/p>\n\n\n\n Most clinical trials are testing whether drugs used to treat other conditions prove helpful for long Covid. Researchers at the University of British Columbia, for example, are looking into low-dose naltrexone<\/a> \u2014 a medication approved for opioid and alcohol use disorder. The drug is thought to have anti-inflammatory and pain-relieving properties, and is used off-label in people with fibromyalgia and ME\/CFS, so it carries potential as a long Covid treatment, Brode said. <\/p>\n\n\n\n Other drugs like baricitinib<\/a>, which is approved to treat rheumatoid arthritis and acute Covid, and temelimab<\/a>, an experimental drug often given to people with multiple sclerosis, are also being investigated as potential long Covid treatments. <\/p>\n\n\n\n In lieu of specific treatments, people with long Covid must balance their rest and activity in a strategy called pacing, Brode said, and receive physical and cognitive behavioral therapy for further support. More often than not, many people end up relying on several drugs, including the antiviral Paxlovid, to treat symptoms.<\/p>\n\n\n\n Realistically, however, \u201cwe may not actually have a single, silver bullet treatment,\u201d said Alison Cohen, an epidemiologist with the University of California, San Francisco who has had long Covid for three years. Long Covid manifests in such a wide variety of ways that it\u2019s going to take a \u201cmultipronged approach\u201d to find effective treatments, Cohen said. <\/p>\n\n\n\nWhat causes long Covid <\/h2>\n\n\n\n
Clues in the eyes, gut and immune system <\/strong><\/h2>\n\n\n\n
Disappointing progress in long Covid treatments<\/h2>\n\n\n\n
What\u2019s ahead for recovery? <\/h2>\n\n\n\n