Hiking is one of Marci Flory's favorite activities, but her chronic Lyme disease sometimes renders her unable to walk. Biotech companies Pfizer and Valneva are testing a vaccine for Lyme disease in a Phase III clinical trial.
For more than two decades, Marci Flory, a 40-year-old emergency room nurse from Lawrence, Kan., has battled the recurring symptoms of chronic Lyme disease, an illness which she believes began after being bitten by a tick during her teenage years.
Over the years, Flory has been plagued by an array of mysterious ailments, ranging from fatigue to crippling pain in her eyes, joints and neck, and even postural tachycardia syndrome or PoTS, an abnormal increase in heart rate after sitting up or standing. Ten years ago, she began to experience the onset of neurological symptoms which ranged from brain fog to sudden headaches, and strange episodes of leg weakness which would leave her unable to walk.
“Initially doctors thought I had ALS, or less likely, multiple sclerosis,” she says. “But after repeated MRI scans for a year, they concluded I had a rare neurological condition called acute transverse myelitis.”
But Flory was not convinced. After ordering a variety of private blood tests, she discovered she was infected with a range of bacteria in the genus Borrelia that live in the guts of ticks, the infectious agents responsible for Lyme disease.
“It made sense,” she says. “Looking back, I was bitten in high school and misdiagnosed with mononucleosis. This was probably the start, and my immune system kept it under wraps for a while. The Lyme bacteria can burrow into every tissue in the body, go into cyst form and become dormant before reactivating.”
The reason why cases of Lyme disease are increasing is down to changing weather patterns, triggered by climate change, meaning that ticks are now found across a much wider geographic range than ever before.
When these species of bacteria are transmitted to humans, they can attack the nervous system, joints and even internal organs which can lead to serious health complications such as arthritis, meningitis and even heart failure. While Lyme disease can sometimes be successfully treated with antibiotics if spotted early on, not everyone responds to these drugs, and for patients who have developed chronic symptoms, there is no known cure. Flory says she knows of fellow Lyme disease patients who have spent hundreds of thousands of dollars seeking treatments.
Concerningly, statistics show that Lyme and other tick-borne diseases are on the rise. Recently released estimates based on health insurance records suggest that at least 476,000 Americans are diagnosed with Lyme disease every year, and many experts believe the true figure is far higher.
The reason why the numbers are growing is down to changing weather patterns, triggered by climate change, meaning that ticks are now found across a much wider geographic range than ever before. Health insurance data shows that cases of Lyme disease have increased fourfold in rural parts of the U.S. over the last 15 years, and 65 percent in urban regions.
As a result, many scientists who have studied Lyme disease feel that it is paramount to bring some form of protective vaccine to market which can be offered to people living in the most at-risk areas.
“Even the increased awareness for Lyme disease has not stopped the cases,” says Eva Sapi, professor of cellular and molecular biology at the University of New Haven. “Some of these patients are looking for answers for years, running from one doctor to another, so that is obviously a very big cost for our society at so many levels.”
Emerging vaccines – and backlash
But with the rising case numbers, interest has grown among the pharmaceutical industry and research communities. Vienna-based biotech Valneva have partnered with Pfizer to take their vaccine – a seasonal jab which offers protection against the six most common strains of Lyme disease in the northern hemisphere – into a Phase III clinical trial which began in August. Involving 6,000 participants in a number of U.S. states and northern Europe where Lyme disease is endemic, it could lead to a licensed vaccine by 2025, if it proves successful.
“For many years Lyme was considered a small market vaccine,” explains Monica E. Embers, assistant professor of parasitology at Tulane University in New Orleans. “Now we know that this is a much bigger problem, Pfizer has stepped up to invest in preventing this disease and other pharmaceutical companies may as well.”
Despite innovations, patient communities and their representatives remain ambivalent about the idea of a vaccine. Some of this skepticism dates back to the failed LYMErix vaccine which was developed in the late 1990s before being withdrawn from the market.
At the same time, scientists at Yale University are developing a messenger RNA vaccine which aims to train the immune system to respond to tick bites by exposing it to 19 proteins found in tick saliva. Whereas the Valneva vaccine targets the bacteria within ticks, the Yale vaccine attempts to provoke an instant and aggressive immune response at the site of the bite. This causes the tick to fall off and limits the potential for transmitting dangerous infections.
But despite these innovations, patient communities and their representatives remain ambivalent about the idea of a vaccine. Some of this skepticism dates back to the failed LYMErix vaccine which was developed in the late 1990s before being withdrawn from the market in 2002 after concerns were raised that it might induce autoimmune reactions in humans.
While this theory was ultimately disproved, the lingering stigma attached to LYMErix meant that most vaccine manufacturers chose to stay away from the disease for many years, something which Gregory Poland, head of the Mayo Clinic’s Vaccine Research Group in Minnesota, describes as a tragedy.
“Since 2002, we have not had a human Lyme vaccine in the U.S. despite the increasing number of cases,” says Poland. “Pretty much everyone in the field thinks they’re ten times higher than the official numbers, so you’re probably talking at least 400,000 each year. It’s an incredible burden but because of concerns about anti-vax protestors, until very recently, no manufacturer has wanted to touch this.”
Such was the backlash surrounding the failed LYMErix program that scientists have even explored the most creative of workarounds for protecting people in tick-populated regions, without needing to actually vaccinate them. One research program at the University of Tennessee came up with the idea of leaving food pellets containing a vaccine in woodland areas with the idea that rodents would eat the pellets, and the vaccine would then kill Borrelia bacteria within any ticks which subsequently fed on the animals.
Even the Pfizer-Valneva vaccine has been cautiously designed to try and allay any lingering concerns, two decades after LYMErix. “The concept is the same as the original LYMErix vaccine, but it has been made safer by removing regions that had the potential to induce autoimmunity,” says Embers. “There will always be individuals who oppose vaccines, Lyme or otherwise, but it will be a tremendous boost to public health to have the option.”
Vaccine alternatives
Researchers are also considering alternative immunization approaches in case sufficiently large numbers of people choose to reject any Lyme vaccine which gets approved. Researchers at UMass Chan Medical School have developed an artificially generated antibody, administered via an annual injection, which is capable of killing Borrelia bacteria in the guts of ticks before they can get into the human host.
So far animal studies have shown it to be 100 percent effective, while the scientists have completed a Phase I trial in which they tested it for safety on 48 volunteers in Nebraska. Because this approach provides the antibody directly, rather than triggering the human immune system to produce the antibody like a vaccine would, Embers predicts that it could be a viable alternative for the vaccine hesitant as well as providing an option for immunocompromised individuals who cannot produce enough of their own antibodies.
At the same time, many patient groups still raise concerns over the fact that numerous diagnostic tests for Lyme disease have been reported to have a poor accuracy. Without this, they argue that it is difficult to prove whether vaccines or any other form of immunization actually work. “If the disease is not understood enough to create a more accurate test and a universally accepted treatment protocol, particularly for those who weren’t treated promptly, how can we be sure about the efficacy of a vaccine?” says Natasha Metcalf, co-founder of the organization Lyme Disease UK.
Flory points out that there are so many different types of Borrelia bacteria which cause Lyme disease, that the immunizations being developed may only stop a proportion of cases. In addition, she says that chronic Lyme patients often report a whole myriad of co-infections which remain poorly understood and are likely to also be involved in the disease process.
Marci Flory undergoes an infusion in an attempt to treat her Lyme disease symptoms.
Marci Flory
“I would love to see an effective Lyme vaccine but I have my reservations,” she says. “I am infected with four types of Borrelia bacteria, plus many co-infections – Babesia, Bartonella, Erlichiosis, Rickettsia, and Mycoplasma – all from a single Douglas County Kansas tick bite. Lyme never travels alone and the vaccine won’t protect against all the many strains of Borrelia and co-infections.”
Valneva CEO Thomas Lingelbach admits that the Pfizer-Valneva vaccine is not perfect, but predicts that it will still have significant impact if approved.
“We expect the vaccine to have 75 percent plus efficacy,” he says. “There is this legacy around the old Lyme vaccines, but the world is very, very different today. The number of clinical manifestations known to be caused by infection with Lyme Borreliosis has significantly increased, and the understanding around severity has certainly increased.”
Embers agrees that while it will still be important for doctors to monitor for other tick-borne infections which are not necessarily covered by the vaccine, having any clinically approved jab would still represent a major step forward in the fight against the disease.
“I think that any vaccine must be properly vetted, and these companies are performing extensive clinical trials to do just that,” she says. “Lyme is the most common tick-borne disease in the U.S. so the public health impact could be significant. However, clinicians and the general public must remain aware of all of the other tick-borne diseases such as Babesia and Anaplasma, and continue to screen for those when a tick bite is suspected.”
Brain coral metaphorically represents the concept of growing organoids in a dish that may eventually attain consciousness--if scientists can first determine what that means.
Few images are more uncanny than that of a brain without a body, fully sentient but afloat in sterile isolation. Such specters have spooked the speculatively-minded since the seventeenth century, when René Descartes declared, "I think, therefore I am."
Since August 29, 2019, the prospect of a bodiless but functional brain has begun to seem far less fantastical.
In Meditations on First Philosophy (1641), the French penseur spins a chilling thought experiment: he imagines "having no hands or eyes, or flesh, or blood or senses," but being tricked by a demon into believing he has all these things, and a world to go with them. A disembodied brain itself becomes a demon in the classic young-adult novel A Wrinkle in Time (1962), using mind control to subjugate a planet called Camazotz. In the sci-fi blockbuster The Matrix (1999), most of humanity endures something like Descartes' nightmare—kept in womblike pods by their computer overlords, who fill the captives' brains with a synthetized reality while tapping their metabolic energy as a power source.
Since August 29, 2019, however, the prospect of a bodiless but functional brain has begun to seem far less fantastical. On that date, researchers at the University of California, San Diego published a study in the journal Cell Stem Cell, reporting the detection of brainwaves in cerebral organoids—pea-size "mini-brains" grown in the lab. Such organoids had emitted random electrical impulses in the past, but not these complex, synchronized oscillations. "There are some of my colleagues who say, 'No, these things will never be conscious,'" lead researcher Alysson Muotri, a Brazilian-born biologist, told The New York Times. "Now I'm not so sure."
Alysson Muotri has no qualms about his creations attaining consciousness as a side effect of advancing medical breakthroughs.
(Credit: ZELMAN STUDIOS)
Muotri's findings—and his avowed ambition to push them further—brought new urgency to simmering concerns over the implications of brain organoid research. "The closer we come to his goal," said Christof Koch, chief scientist and president of the Allen Brain Institute in Seattle, "the more likely we will get a brain that is capable of sentience and feeling pain, agony, and distress." At the annual meeting of the Society for Neuroscience, researchers from the Green Neuroscience Laboratory in San Diego called for a partial moratorium, warning that the field was "perilously close to crossing this ethical Rubicon and may have already done so."
Yet experts are far from a consensus on whether brain organoids can become conscious, whether that development would necessarily be dreadful—or even how to tell if it has occurred.
So how worried do we need to be?
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An organoid is a miniaturized, simplified version of an organ, cultured from various types of stem cells. Scientists first learned to make them in the 1980s, and have since turned out mini-hearts, lungs, kidneys, intestines, thyroids, and retinas, among other wonders. These creations can be used for everything from observation of basic biological processes to testing the effects of gene variants, pathogens, or medications. They enable researchers to run experiments that might be less accurate using animal models and unethical or impractical using actual humans. And because organoids are three-dimensional, they can yield insights into structural, developmental, and other matters that an ordinary cell culture could never provide.
In 2006, Japanese biologist Shinya Yamanaka developed a mix of proteins that turned skin cells into "pluripotent" stem cells, which could subsequently be transformed into neurons, muscle cells, or blood cells. (He later won a Nobel Prize for his efforts.) Developmental biologist Madeline Lancaster, then a post-doctoral student at the Institute of Molecular Biotechnology in Vienna, adapted that technique to grow the first brain organoids in 2013. Other researchers soon followed suit, cultivating specialized mini-brains to study disorders ranging from microcephaly to schizophrenia.
Muotri, now a youthful 45-year-old, was among the boldest of these pioneers. His team revealed the process by which Zika virus causes brain damage, and showed that sofosbuvir, a drug previously approved for hepatitis C, protected organoids from infection. He persuaded NASA to fly his organoids to the International Space Station, where they're being used to trace the impact of microgravity on neurodevelopment. He grew brain organoids using cells implanted with Neanderthal genes, and found that their wiring differed from organoids with modern DNA.
Like the latter experiment, Muotri's brainwave breakthrough emerged from a longtime obsession with neuroarchaeology. "I wanted to figure out how the human brain became unique," he told me in a phone interview. "Compared to other species, we are very social. So I looked for conditions where the social brain doesn't function well, and that led me to autism." He began investigating how gene variants associated with severe forms of the disorder affected neural networks in brain organoids.
Tinkering with chemical cocktails, Muotri and his colleagues were able to keep their organoids alive far longer than earlier versions, and to culture more diverse types of brain cells. One team member, Priscilla Negraes, devised a way to measure the mini-brains' electrical activity, by planting them in a tray lined with electrodes. By four months, the researchers found to their astonishment, normal organoids (but not those with an autism gene) emitted bursts of synchronized firing, separated by 20-second silences. At nine months, the organoids were producing up to 300,000 spikes per minute, across a range of frequencies.
He shared his vision for "brain farms," which would grow organoids en masse for drug development or tissue transplants.
When the team used an artificial intelligence system to compare these patterns with EEGs of gestating fetuses, the program found them to be nearly identical at each stage of development. As many scientists noted when the news broke, that didn't mean the organoids were conscious. (Their chaotic bursts bore little resemblance to the orderly rhythms of waking adult brains.) But to some observers, it suggested that they might be approaching the borderline.
***
Shortly after Muotri's team published their findings, I attended a conference at UCSD on the ethical questions they raised. The scientist, in jeans and a sky-blue shirt, spoke rhapsodically of brain organoids' potential to solve scientific mysteries and lead to new medical treatments. He showed video of a spider-like robot connected to an organoid through a computer interface. The machine responded to different brainwave patterns by walking or stopping—the first stage, Muotri hoped, in teaching organoids to communicate with the outside world. He described his plans to develop organoids with multiple brain regions, and to hook them up to retinal organoids so they could "see." He shared his vision for "brain farms," which would grow organoids en masse for drug development or tissue transplants.
Muotri holds a spider-like robot that can connect to an organoid through a computer interface.
(Credit: ROLAND LIZARONDO/KPBS)
Yet Muotri also stressed the current limitations of the technology. His organoids contain approximately 2 million neurons, compared to about 200 million in a rat's brain and 86 billion in an adult human's. They consist only of a cerebral cortex, and lack many of a real brain's cell types. Because researchers haven't yet found a way to give organoids blood vessels, moreover, nutrients can't penetrate their inner recesses—a severe constraint on their growth.
Another panelist strongly downplayed the imminence of any Rubicon. Patricia Churchland, an eminent philosopher of neuroscience, cited research suggesting that in mammals, networked connections between the cortex and the thalamus are a minimum requirement for consciousness. "It may be a blessing that you don't have the enabling conditions," she said, "because then you don't have the ethical issues."
Christof Koch, for his part, sounded much less apprehensive than the Times had made him seem. He noted that science lacks a definition of consciousness, beyond an organism's sense of its own existence—"the fact that it feels like something to be you or me." As to the competing notions of how the phenomenon arises, he explained, he prefers one known as Integrated Information Theory, developed by neuroscientist Giulio Tononi. IIT considers consciousness to be a quality intrinsic to systems that reach a certain level of complexity, integration, and causal power (the ability for present actions to determine future states). By that standard, Koch doubted that brain organoids had stepped over the threshold.
One way to tell, he said, might be to use the "zap and zip" test invented by Tononi and his colleague Marcello Massimini in the early 2000s to determine whether patients are conscious in the medical sense. This technique zaps the brain with a pulse of magnetic energy, using a coil held to the scalp. As loops of neural impulses cascade through the cerebral circuitry, an EEG records the firing patterns. In a waking brain, the feedback is highly complex—neither totally predictable nor totally random. In other states, such as sleep, coma, or anesthesia, the rhythms are simpler. Applying an algorithm commonly used for computer "zip" files, the researchers devised a scale that allowed them to correctly diagnose most patients who were minimally conscious or in a vegetative state.
If scientists could find a way to apply "zap and zip" to brain organoids, Koch ventured, it should be possible to rank their degree of awareness on a similar scale. And if it turned out that an organoid was conscious, he added, our ethical calculations should strive to minimize suffering, and avoid it where possible—just as we now do, or ought to, with animal subjects. (Muotri, I later learned, was already contemplating sensors that would signal when organoids were likely in distress.)
During the question-and-answer period, an audience member pressed Churchland about how her views might change if the "enabling conditions" for consciousness in brain organoids were to arise. "My feeling is, we'll answer that when we get there," she said. "That's an unsatisfying answer, but it's because I don't know. Maybe they're totally happy hanging out in a dish! Maybe that's the way to be."
***
Muotri himself admits to no qualms about his creations attaining consciousness, whether sooner or later. "I think we should try to replicate the model as close as possible to the human brain," he told me after the conference. "And if that involves having a human consciousness, we should go in that direction." Still, he said, if strong evidence of sentience does arise, "we should pause and discuss among ourselves what to do."
"The field is moving so rapidly, you blink your eyes and another advance has occurred."
Churchland figures it will be at least a decade before anyone reaches the crossroads. "That's partly because the thalamus has a very complex architecture," she said. It might be possible to mimic that architecture in the lab, she added, "but I tend to think it's not going to be a piece of cake."
If anything worries Churchland about brain organoids, in fact, it's that Muotri's visionary claims for their potential could set off a backlash among those who find them unacceptably spooky. "Alysson has done brilliant work, and he's wonderfully charismatic and charming," she said. "But then there's that guy back there who doesn't think it's exciting; he thinks you're the Devil incarnate. You're playing into the hands of people who are going to shut you down."
Koch, however, is more willing to indulge Muotri's dreams. "Ten years ago," he said, "nobody would have believed you can take a stem cell and get an entire retina out of it. It's absolutely frigging amazing. So who am I to say the same thing can't be true for the thalamus or the cortex? The field is moving so rapidly, you blink your eyes and another advance has occurred."
The point, he went on, is not to build a Cartesian thought experiment—or a Matrix-style dystopia—but to vanquish some of humankind's most terrifying foes. "You know, my dad passed away of Parkinson's. I had a twin daughter; she passed away of sudden death syndrome. One of my best friends killed herself; she was schizophrenic. We want to eliminate all these terrible things, and that requires experimentation. We just have to go into it with open eyes."