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."
Meet Dr. Renee Wegrzyn, the first Director of President Biden's new health agency, ARPA-H
In today’s podcast episode, I talk with Renee Wegrzyn, appointed by President Biden as the first director of a health agency created last year, the Advanced Research Projects Agency for Health, or ARPA-H. It’s inspired by DARPA, the agency that develops innovations for the Defense department and has been credited with hatching world-changing technologies such as ARPANET, which became the internet.
Time will tell if ARPA-H will lead to similar achievements in the realm of health. That’s what President Biden and Congress expect in return for funding ARPA-H at 2.5 billion dollars over three years.
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How will the agency figure out which projects to take on, especially with so many patient advocates for different diseases demanding moonshot funding for rapid progress?
I talked with Dr. Wegrzyn about the opportunities and challenges, what lessons ARPA-H is borrowing from Operation Warp Speed, how she decided on the first ARPA-H project that was announced recently, why a separate agency was needed instead of reforming HHS and the National Institutes of Health to be better at innovation, and how ARPA-H will make progress on disease prevention in addition to treatments for cancer, Alzheimer’s and diabetes, among many other health priorities.
Dr. Wegrzyn’s resume leaves no doubt of her suitability for this role. She was a program manager at DARPA where she focused on applying gene editing and synthetic biology to the goal of improving biosecurity. For her work there, she received the Superior Public Service Medal and, in case that wasn’t enough ARPA experience, she also worked at another ARPA that leads advanced projects in intelligence, called I-ARPA. Before that, she ran technical teams in the private sector working on gene therapies and disease diagnostics, among other areas. She has been a vice president of business development at Gingko Bioworks and headed innovation at Concentric by Gingko. Her training and education includes a PhD and undergraduate degree in applied biology from the Georgia Institute of Technology and she did her postdoc as an Alexander von Humboldt Fellow in Heidelberg, Germany.
Dr. Wegrzyn told me that she’s “in the hot seat.” The pressure is on for ARPA-H especially after the need and potential for health innovation was spot lit by the pandemic and the unprecedented speed of vaccine development. We'll soon find out if ARPA-H can produce gamechangers in health that are equivalent to DARPA’s creation of the internet.
Show links:
ARPA-H - https://arpa-h.gov/
Dr. Wegrzyn profile - https://arpa-h.gov/people/renee-wegrzyn/
Dr. Wegrzyn Twitter - https://twitter.com/rwegrzyn?lang=en
President Biden Announces Dr. Wegrzyn's appointment - https://www.whitehouse.gov/briefing-room/statement...
Leaps.org coverage of ARPA-H - https://leaps.org/arpa/
ARPA-H program for joints to heal themselves - https://arpa-h.gov/news/nitro/ -
ARPA-H virtual talent search - https://arpa-h.gov/news/aco-talent-search/
Dr. Renee Wegrzyn was appointed director of ARPA-H last October.
Tiny, tough “water bears” may help bring new vaccines and medicines to sub-Saharan Africa
Microscopic tardigrades, widely considered to be some of the toughest animals on earth, can survive for decades without oxygen or water and are thought to have lived through a crash-landing on the moon. Also known as water bears, they survive by fully dehydrating and later rehydrating themselves – a feat only a few animals can accomplish. Now scientists are harnessing tardigrades’ talents to make medicines that can be dried and stored at ambient temperatures and later rehydrated for use—instead of being kept refrigerated or frozen.
Many biologics—pharmaceutical products made by using living cells or synthesized from biological sources—require refrigeration, which isn’t always available in many remote locales or places with unreliable electricity. These products include mRNA and other vaccines, monoclonal antibodies and immuno-therapies for cancer, rheumatoid arthritis and other conditions. Cooling is also needed for medicines for blood clotting disorders like hemophilia and for trauma patients.
Formulating biologics to withstand drying and hot temperatures has been the holy grail for pharmaceutical researchers for decades. It’s a hard feat to manage. “Biologic pharmaceuticals are highly efficacious, but many are inherently unstable,” says Thomas Boothby, assistant professor of molecular biology at University of Wyoming. Therefore, during storage and shipping, they must be refrigerated at 2 to 8 degrees Celsius (35 to 46 degrees Fahrenheit). Some must be frozen, typically at -20 degrees Celsius, but sometimes as low -90 degrees Celsius as was the case with the Pfizer Covid vaccine.
For Covid, fewer than 73 percent of the global population received even one dose. The need for refrigerated or frozen handling was partially to blame.
The costly cold chain
The logistics network that ensures those temperature requirements are met from production to administration is called the cold chain. This cold chain network is often unreliable or entirely lacking in remote, rural areas in developing nations that have malfunctioning electrical grids. “Almost all routine vaccines require a cold chain,” says Christopher Fox, senior vice president of formulations at the Access to Advanced Health Institute. But when the power goes out, so does refrigeration, putting refrigerated or frozen medical products at risk. Consequently, the mRNA vaccines developed for Covid-19 and other conditions, as well as more traditional vaccines for cholera, tetanus and other diseases, often can’t be delivered to the most remote parts of the world.
To understand the scope of the challenge, consider this: In the U.S., more than 984 million doses of Covid-19 vaccine have been distributed so far. Each one needed refrigeration that, even in the U.S., proved challenging. Now extrapolate to all vaccines and the entire world. For Covid, fewer than 73 percent of the global population received even one dose. The need for refrigerated or frozen handling was partially to blame.
Globally, the cold chain packaging market is valued at over $15 billion and is expected to exceed $60 billion by 2033.
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Freeze-drying, also called lyophilization, which is common for many vaccines, isn’t always an option. Many freeze-dried vaccines still need refrigeration, and even medicines approved for storage at ambient temperatures break down in the heat of sub-Saharan Africa. “Even in a freeze-dried state, biologics often will undergo partial rehydration and dehydration, which can be extremely damaging,” Boothby explains.
The cold chain is also very expensive to maintain. The global pharmaceutical cold chain packaging market is valued at more than $15 billion, and is expected to exceed $60 billion by 2033, according to a report by Future Market Insights. This cost is only expected to grow. According to the consulting company Accenture, the number of medicines that require the cold chain are expected to grow by 48 percent, compared to only 21 percent for non-cold-chain therapies.
Tardigrades to the rescue
Tardigrades are only about a millimeter long – with four legs and claws, and they lumber around like bears, thus their nickname – but could provide a big solution. “Tardigrades are unique in the animal kingdom, in that they’re able to survive a vast array of environmental insults,” says Boothby, the Wyoming professor. “They can be dried out, frozen, heated past the boiling point of water and irradiated at levels that are thousands of times more than you or I could survive.” So, his team is gradually unlocking tardigrades’ survival secrets and applying them to biologic pharmaceuticals to make them withstand both extreme heat and desiccation without losing efficacy.
Boothby’s team is focusing on blood clotting factor VIII, which, as the name implies, causes blood to clot. Currently, Boothby is concentrating on the so-called cytoplasmic abundant heat soluble (CAHS) protein family, which is found only in tardigrades, protecting them when they dry out. “We showed we can desiccate a biologic (blood clotting factor VIII, a key clotting component) in the presence of tardigrade proteins,” he says—without losing any of its effectiveness.
The researchers mixed the tardigrade protein with the blood clotting factor and then dried and rehydrated that substance six times without damaging the latter. This suggests that biologics protected with tardigrade proteins can withstand real-world fluctuations in humidity.
Furthermore, Boothby’s team found that when the blood clotting factor was dried and stabilized with tardigrade proteins, it retained its efficacy at temperatures as high as 95 degrees Celsius. That’s over 200 degrees Fahrenheit, much hotter than the 58 degrees Celsius that the World Meteorological Organization lists as the hottest recorded air temperature on earth. In contrast, without the protein, the blood clotting factor degraded significantly. The team published their findings in the journal Nature in March.
Although tardigrades rarely live more than 2.5 years, they have survived in a desiccated state for up to two decades, according to Animal Diversity Web. This suggests that tardigrades’ CAHS protein can protect biologic pharmaceuticals nearly indefinitely without refrigeration or freezing, which makes it significantly easier to deliver them in locations where refrigeration is unreliable or doesn’t exist.
The tricks of the tardigrades
Besides the CAHS proteins, tardigrades rely on a type of sugar called trehalose and some other protectants. So, rather than drying up, their cells solidify into rigid, glass-like structures. As that happens, viscosity between cells increases, thereby slowing their biological functions so much that they all but stop.
Now Boothby is combining CAHS D, one of the proteins in the CAHS family, with trehalose. He found that CAHS D and trehalose each protected proteins through repeated drying and rehydrating cycles. They also work synergistically, which means that together they might stabilize biologics under a variety of dry storage conditions.
“We’re finding the protective effect is not just additive but actually is synergistic,” he says. “We’re keen to see if something like that also holds true with different protein combinations.” If so, combinations could possibly protect against a variety of conditions.
Commercialization outlook
Before any stabilization technology for biologics can be commercialized, it first must be approved by the appropriate regulators. In the U.S., that’s the U.S. Food and Drug Administration. Developing a new formulation would require clinical testing and vast numbers of participants. So existing vaccines and biologics likely won’t be re-formulated for dry storage. “Many were developed decades ago,” says Fox. “They‘re not going to be reformulated into thermo-stable vaccines overnight,” if ever, he predicts.
Extending stability outside the cold chain, even for a few days, can have profound health, environmental and economic benefits.
Instead, this technology is most likely to be used for the new products and formulations that are just being created. New and improved vaccines will be the first to benefit. Good candidates include the plethora of mRNA vaccines, as well as biologic pharmaceuticals for neglected diseases that affect parts of the world where reliable cold chain is difficult to maintain, Boothby says. Some examples include new, more effective vaccines for malaria and for pathogenic Escherichia coli, which causes diarrhea.
Tallying up the benefits
Extending stability outside the cold chain, even for a few days, can have profound health, environmental and economic benefits. For instance, MenAfriVac, a meningitis vaccine (without tardigrade proteins) developed for sub-Saharan Africa, can be stored at up to 40 degrees Celsius for four days before administration. “If you have a few days where you don’t need to maintain the cold chain, it’s easier to transport vaccines to remote areas,” Fox says, where refrigeration does not exist or is not reliable.
Better health is an obvious benefit. MenAfriVac reduced suspected meningitis cases by 57 percent in the overall population and more than 99 percent among vaccinated individuals.
Lower healthcare costs are another benefit. One study done in Togo found that the cold chain-related costs increased the per dose vaccine price up to 11-fold. The ability to ship the vaccines using the usual cold chain, but transporting them at ambient temperatures for the final few days cut the cost in half.
There are environmental benefits, too, such as reducing fuel consumption and greenhouse gas emissions. Cold chain transports consume 20 percent more fuel than non-cold chain shipping, due to refrigeration equipment, according to the International Trade Administration.
A study by researchers at Johns Hopkins University compared the greenhouse gas emissions of the new, oral Vaxart COVID-19 vaccine (which doesn’t require refrigeration) with four intramuscular vaccines (which require refrigeration or freezing). While the Vaxart vaccine is still in clinical trials, the study found that “up to 82.25 million kilograms of CO2 could be averted by using oral vaccines in the U.S. alone.” That is akin to taking 17,700 vehicles out of service for one year.
Although tardigrades’ protective proteins won’t be a component of biologic pharmaceutics for several years, scientists are proving that this approach is viable. They are hopeful that a day will come when vaccines and biologics can be delivered anywhere in the world without needing refrigerators or freezers en route.