How Seriously Should We Take the Promising News on Long COVID?
One of the biggest challenges of the COVID-19 pandemic is the way in which it has forced us to question our hopes. In normal times, hope is a tonic we take in small doses to keep us moving forward through the slog of daily life. The pandemic, however, has made it a much scarcer commodity, spurring us not only to seek it more desperately but to scrutinize it more closely.
Every bit of reassurance seems to come with caveats: Masks can shield us from the coronavirus, but they may need to be doubled in some situations to provide adequate protection. Vaccines work, but they may not be as effective against some viral variants—and they can cause extremely rare but serious side effects. Every few weeks, another potential miracle cure makes headlines (Hydroxychloroquine! Convalescent plasma!), only to prove disappointing on closer inspection. It's hard to know which alleged breakthroughs are worth pinning our hopes on, and which are the products of wishful thinking or hucksterism.
In January 2021, a study published in the journal Gut offered evidence that bacteria in the intestines might influence a whole spectrum of symptoms in long-haul patients.
Lately, two possible sources of hope have emerged concerning so-called "long COVID"—the debilitating syndrome, estimated to affect up to one-third of patients, in which physical, neurological, and cognitive symptoms persist for months. The first encouraging item has gotten plenty of media attention: reports that some long-haulers feel better after being vaccinated. The second item, while less widely covered, has caused a stir among scientists: a study suggesting that rebalancing the gut microbiome—the community of microorganisms in our intestines—could decrease both the severity and duration of the illness.
How optimistic should we allow ourselves to be about either of these developments? Experts warn that it's too soon to tell. Yet research into how vaccines and gut bacteria affect long-haulers—and how both factors might work together—could eventually help solve key pieces of the pandemic puzzle.
Investigating the Role of the Gut Microbiome
The idea that there may be a link between COVID-19 and gut health comes as no surprise to Jessica Lovett. Her case began in June 2020 with gastrointestinal distress—a symptom that was just beginning to be recognized as commonplace in what had initially been considered a respiratory illness. "I had diarrhea three to five times a day for two months," Lovett recalls. "I lost a lot of weight." By July, she was also suffering shortness of breath, chest pain, racing heartbeat, severe fatigue, brain fog, migraines, memory lapses, and more. As with many other COVID long-haulers, these troubles waxed and waned in an endless parade.
Lovett was the marketing manager for a music school in Austin, Texas, and the mother of a two-year-old boy. Just before she got sick, she ran a 5K race for her 40th birthday. Afterward, she had to give up her job, stop driving, and delegate childcare to her husband (who fell ill shortly before she did but recovered in 12 days). Tests showed no visible damage to her lungs, heart, or other organs. But she felt intuitively that taming her GI troubles would be key to getting well. On the advice of fellow patients in a long-COVID Facebook group—and, later, with the guidance of a doctor—she tried avoiding foods thought to trigger histamine reactions or inflammation. That seemed to help some, as did nutritional supplements, antihistamines, and angina medications. Still, she relapsed frequently, and was often bedridden.
In January 2021, a study published in the journal Gut offered evidence that bacteria in the intestines might influence a whole spectrum of symptoms in patients like Lovett. Researchers at the Chinese University of Hong Kong examined blood and stool samples and medical records from 100 hospital patients with lab-confirmed COVID-19 infections, and from 78 people without the disease who were taking part in a microbiome study before the pandemic.
The team, led by professor Siew Chien Ng, found that the makeup of the gut microbiome differed sharply between the two groups. Patients with COVID had higher levels of three bacterial species than those without the infection, but lower levels of several species known to enhance immune system response. Reductions in two of those species—Faecalibacterium prausnitzii and Bifidobacterium bifidum—were associated with more severe symptoms. And the numbers of such helpful bacteria remained low in stool samples collected up to 30 days after infected patients had seemingly cleared the coronavirus from their bodies.
Analysis of blood samples, moreover, showed that these bacterial imbalances correlated with higher levels of inflammatory cytokines (immune system chemicals that are elevated in many patients with severe COVID-19) and markers of tissue damage, such as C-reactive protein.
These findings led the researchers to suggest that rebalancing the microbiome might lessen not only the intensity of COVID symptoms, but also their persistence. "Bolstering of beneficial gut species depleted in COVID-19," they wrote, "could serve as a novel avenue to mitigate severe disease, underscoring the importance of managing patients' gut biota during and after COVID-19."
Soon afterward, Ng revealed that she was working on a solution. Her team, she told Medscape, had developed "a microbiome immunity product that is targeted to what is missing in COVID-19 patients." Early research showed that hospitalized patients who received the treatment developed more antibodies, had fewer symptoms, and were discharged sooner. "So it is quite a bright and promising future," she enthused, "in alleviating some of these detrimental effects of the virus."
The Chicken-and-Egg Problem
Ng's study isn't the only one to suggest a connection between the gut and long COVID. Researchers led by gastroenterologist Saurabh Mehandru at New York's Mount Sinai Hospital recently determined that SARS-CoV-2, the virus that causes COVID-19, can linger in the intestines for months after a patient tests negative. Some studies have also found that gastrointestinal symptoms in the acute phase of the illness correlate with poorer outcomes—though that's far from settled. (In another study, Mehandru's team found lower mortality among patients presenting with GI symptoms.) But the Hong Kong group's paper was the first to posit that resident microbes may play a decisive role in the disease.
That view reflects growing evidence that these bugs can influence a range of ailments, from diabetes to schizophrenia. Over the past decade, the gut microbiome has emerged as a central regulator of the immune system. Some intestinal bacteria emit chemicals that signal immune cells to reduce production of inflammatory proteins, or help those cells effectively target invading pathogens. They also help maintain the integrity of the intestinal lining—preventing the syndrome known as "leaky gut," in which harmful microbes or toxins penetrate to the underlying tissue, potentially wreaking havoc throughout the body and brain.
Nonetheless, many experts have responded to Ng's findings with distinct caution. One problem, they point out, is the chicken-and-egg question: Do reduced levels of beneficial gut bacteria trigger the inflammation seen in COVID-19, or does inflammation triggered by COVID-19 kill off beneficial gut bacteria? "It's an issue of causality versus just association," explains Somsouk Ma, a professor of gastroenterology at the University of California, San Francisco. "I tend to think that the shift in microbes is more likely a consequence of the infection. But, of course, that's just speculation."
A related issue is whether a pill that replenishes "good" bacteria can really combat the effects of COVID-19—whether acute or chronic. Although scientists are studying fecal transplants and other probiotic therapies for many disorders, none has yet been approved by the U.S Food and Drug Administration. "The only situation where bacterial transplantation is known to work is in a form of colitis called Clostridium difficile," notes Mehandru. "I think it's a bit premature to lay too much emphasis on this in the context of COVID."
Placebo-controlled clinical trials will be needed to determine the efficacy of Ng's approach. (Consumer warning: The bacteria she's employing are not found in commercially available probiotics.) Whatever the results, such research—along with studies that track patients' gut microbiomes before, during, and after COVID-19 infection—could help scientists understand why some people have such trouble kicking the disease.
An Unexpected Benefit of Vaccines
The question of what causes long COVID is also central to understanding the effects of vaccines on the condition. In March, as inoculation campaigns took off across the nation, many long-haulers were delighted to see their symptoms disappear within days of getting the shot. "I woke up and it was like, 'Oh what a beautiful morning,'" one patient told The New York Times.
Yet the effects have been far from uniform. Although scientific surveys have not yet been conducted, an April poll by a Facebook group called Survivor Corps found numbers close to experts' estimates: 39 percent said they experienced partial to full recovery post-vaccination; 46 percent saw no difference; and 14 percent felt worse.
How could vaccines—which are designed to prevent COVID-19, not cure it—help some chronic patients get well? In a blog post, Yale immunologist Akiko Iwasaki suggested that the answer depends on what is driving a particular patient's symptoms. Iwasaki identified three possible mechanisms behind long COVID: 1) a persistent viral reservoir; 2) a "viral ghost," composed of fragments of the virus (RNA or proteins) that linger after the infection has been cleared but can still stimulate inflammation; and 3) an autoimmune response triggered by the infection, inducing a patient's immune cells to attack her own tissues.
These mechanisms "are not mutually exclusive," Iwasaki wrote, "and all three might benefit from the vaccines." If a patient has a viral reservoir, vaccine-induced immune cells and antibodies might be able to eliminate it. If the patient has a viral ghost, those vaccine-primed immune responses might knock it out as well. And if the patient is suffering from a COVID-triggered autoimmune syndrome, the vaccine might act as a decoy, shifting the immune system's attention to antigens contained in the shot (and perhaps reprogramming autoimmune cells in the process). The varying role of these underlying factors, and possibly others—such as the gut microbiome—might also help explain why vaccines don't benefit all long-haulers equally. Iwasaki and her team recently launched a clinical study to investigate this theory.
Pato Hebert, a professor of art and public policy at NYU, contracted COVID-19 in March 2020 while on sabbatical in Los Angeles. Hebert, then 50, started out with mild flu-like symptoms, but he was slammed with fatigue, headaches, and confusion a week after testing positive. In April, he landed in urgent care with severe shortness of breath. His brain fog worsened that summer, and a gentle swim brought on a dizzy spell so overwhelming that he feared it was a stroke. (Thankfully, tests showed it wasn't.) In September, he developed severe GI issues, which came and went over the following months. He found some relief through medications, dietary adjustments, acupuncture, herbal remedies, and careful conservation of his physical and mental energy—but a year after his diagnosis, he was still sick.
Hebert received his first dose of the Moderna vaccine on March 1, 2021; it made no difference in his symptoms. After his second dose, on the 29th, he suffered terrible headaches—"like early COVID days," he told me. A week later, his condition had improved slightly compared to pre-vaccination. "With a few exceptions, my fatigue and brain fog have been less challenging," he reported. "I'm cautiously optimistic." But in late April, he suffered another flareup of respiratory and GI issues.
For Jessica Lovett, the vaccine's effects were more dramatic. After her first dose of the Pfizer-BioNTech formula, on February 26, her cognitive symptoms improved enough that she was able to drive again; within a week, she was pushing her son uphill in a stroller, lifting light weights, and running for short distances. After the second dose, she says, "I had incredible energy. It was insane, like I drank three cups of coffee."
Lovett (who now runs a Facebook support group for Austin locals, ATX Covid Long Haulers) stresses that the vaccine hasn't cured her. She winds up back in bed whenever she pushes herself too hard. She still needs to take antihistamines and shun certain foodstuffs; any slip-up brings another relapse. Yet she's able to live more fully than at any time since she fell ill—and she has begun to feel a renewed sense of hope.
Recently, in fact, she and her husband decided to expand their family. "I guess that tells you something," she says with a laugh. "The doctors have given us the okay, and we're going to try."
Have You Heard of the Best Sport for Brain Health?
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
Here are the promising studies covered in this week's Friday Five:
- Reprogram cells to a younger state
- Pick up this sport for brain health
- Do all mental illnesses have the same underlying cause?
- New test could diagnose autism in newborns
- Scientists 3D print an ear and attach it to woman
Can blockchain help solve the Henrietta Lacks problem?
Science has come a long way since Henrietta Lacks, a Black woman from Baltimore, succumbed to cervical cancer at age 31 in 1951 -- only eight months after her diagnosis. Since then, research involving her cancer cells has advanced scientific understanding of the human papilloma virus, polio vaccines, medications for HIV/AIDS and in vitro fertilization.
Today, the World Health Organization reports that those cells are essential in mounting a COVID-19 response. But they were commercialized without the awareness or permission of Lacks or her family, who have filed a lawsuit against a biotech company for profiting from these “HeLa” cells.
While obtaining an individual's informed consent has become standard procedure before the use of tissues in medical research, many patients still don’t know what happens to their samples. Now, a new phone-based app is aiming to change that.
Tissue donors can track what scientists do with their samples while safeguarding privacy, through a pilot program initiated in October by researchers at the Johns Hopkins Berman Institute of Bioethics and the University of Pittsburgh’s Institute for Precision Medicine. The program uses blockchain technology to offer patients this opportunity through the University of Pittsburgh's Breast Disease Research Repository, while assuring that their identities remain anonymous to investigators.
A blockchain is a digital, tamper-proof ledger of transactions duplicated and distributed across a computer system network. Whenever a transaction occurs with a patient’s sample, multiple stakeholders can track it while the owner’s identity remains encrypted. Special certificates called “nonfungible tokens,” or NFTs, represent patients’ unique samples on a trusted and widely used blockchain that reinforces transparency.
Blockchain could be used to notify people if cancer researchers discover that they have certain risk factors.
“Healthcare is very data rich, but control of that data often does not lie with the patient,” said Julius Bogdan, vice president of analytics for North America at the Healthcare Information and Management Systems Society (HIMSS), a Chicago-based global technology nonprofit. “NFTs allow for the encapsulation of a patient’s data in a digital asset controlled by the patient.” He added that this technology enables a more secure and informed method of participating in clinical and research trials.
Without this technology, de-identification of patients’ samples during biomedical research had the unintended consequence of preventing them from discovering what researchers find -- even if that data could benefit their health. A solution was urgently needed, said Marielle Gross, assistant professor of obstetrics, gynecology and reproductive science and bioethics at the University of Pittsburgh School of Medicine.
“A researcher can learn something from your bio samples or medical records that could be life-saving information for you, and they have no way to let you or your doctor know,” said Gross, who is also an affiliate assistant professor at the Berman Institute. “There’s no good reason for that to stay the way that it is.”
For instance, blockchain could be used to notify people if cancer researchers discover that they have certain risk factors. Gross estimated that less than half of breast cancer patients are tested for mutations in BRCA1 and BRCA2 — tumor suppressor genes that are important in combating cancer. With normal function, these genes help prevent breast, ovarian and other cells from proliferating in an uncontrolled manner. If researchers find mutations, it’s relevant for a patient’s and family’s follow-up care — and that’s a prime example of how this newly designed app could play a life-saving role, she said.
Liz Burton was one of the first patients at the University of Pittsburgh to opt for the app -- called de-bi, which is short for decentralized biobank -- before undergoing a mastectomy for early-stage breast cancer in November, after it was diagnosed on a routine mammogram. She often takes part in medical research and looks forward to tracking her tissues.
“Anytime there’s a scientific experiment or study, I’m quick to participate -- to advance my own wellness as well as knowledge in general,” said Burton, 49, a life insurance service representative who lives in Carnegie, Pa. “It’s my way of contributing.”
Liz Burton was one of the first patients at the University of Pittsburgh to opt for the app before undergoing a mastectomy for early-stage breast cancer.
Liz Burton
The pilot program raises the issue of what investigators may owe study participants, especially since certain populations, such as Black and indigenous peoples, historically were not treated in an ethical manner for scientific purposes. “It’s a truly laudable effort,” Tamar Schiff, a postdoctoral fellow in medical ethics at New York University’s Grossman School of Medicine, said of the endeavor. “Research participants are beautifully altruistic.”
Lauren Sankary, a bioethicist and associate director of the neuroethics program at Cleveland Clinic, agrees that the pilot program provides increased transparency for study participants regarding how scientists use their tissues while acknowledging individuals’ contributions to research.
However, she added, “it may require researchers to develop a process for ongoing communication to be responsive to additional input from research participants.”
Peter H. Schwartz, professor of medicine and director of Indiana University’s Center for Bioethics in Indianapolis, said the program is promising, but he wonders what will happen if a patient has concerns about a particular research project involving their tissues.
“I can imagine a situation where a patient objects to their sample being used for some disease they’ve never heard about, or which carries some kind of stigma like a mental illness,” Schwartz said, noting that researchers would have to evaluate how to react. “There’s no simple answer to those questions, but the technology has to be assessed with an eye to the problems it could raise.”
To truly make a difference, blockchain must enable broad consent from patients, not just de-identification.
As a result, researchers may need to factor in how much information to share with patients and how to explain it, Schiff said. There are also concerns that in tracking their samples, patients could tell others what they learned before researchers are ready to publicly release this information. However, Bogdan, the vice president of the HIMSS nonprofit, believes only a minimal study identifier would be stored in an NFT, not patient data, research results or any type of proprietary trial information.
Some patients may be confused by blockchain and reluctant to embrace it. “The complexity of NFTs may prevent the average citizen from capitalizing on their potential or vendors willing to participate in the blockchain network,” Bogdan said. “Blockchain technology is also quite costly in terms of computational power and energy consumption, contributing to greenhouse gas emissions and climate change.”
In addition, this nascent, groundbreaking technology is immature and vulnerable to data security flaws, disputes over intellectual property rights and privacy issues, though it does offer baseline protections to maintain confidentiality. To truly make a difference, blockchain must enable broad consent from patients, not just de-identification, said Robyn Shapiro, a bioethicist and founding attorney at Health Sciences Law Group near Milwaukee.
The Henrietta Lacks story is a prime example, Shapiro noted. During her treatment for cervical cancer at Johns Hopkins, Lacks’s tissue was de-identified (albeit not entirely, because her cell line, HeLa, bore her initials). After her death, those cells were replicated and distributed for important and lucrative research and product development purposes without her knowledge or consent.
Nonetheless, Shapiro thinks that the initiative by the University of Pittsburgh and Johns Hopkins has potential to solve some ethical challenges involved in research use of biospecimens. “Compared to the system that allowed Lacks’s cells to be used without her permission, Shapiro said, “blockchain technology using nonfungible tokens that allow patients to follow their samples may enhance transparency, accountability and respect for persons who contribute their tissue and clinical data for research.”
Read more about laws that have prevented people from the rights to their own cells.