Masks and Distancing Won't Be Enough to Prevent School Outbreaks, Latest Science Suggests
Never has the prospect of "back to school" seemed so ominous as it does in 2020. As the number of COVID-19 cases climb steadily in nearly every state, the prospect of in-person classes are filling students, parents, and faculty alike with a corresponding sense of dread.
The notion that children are immune or resistant to SARS-CoV-2 is demonstrably untrue.
The decision to resume classes at primary, secondary, and collegiate levels is not one that should be regarded lightly, particularly as coronavirus cases skyrocket across the United States.
What should be a measured, data-driven discussion that weighs risks and benefits has been derailed by political talking points. President Trump has been steadily advocating for an unfettered return to the classroom, often through imperative "OPEN THE SCHOOLS!!!" tweets. In July, Secretary of Education Betsy DeVos threatened to withhold funding from schools that did not reopen for full-time, in-person classes, despite not having the authority to do so. Like so many public health issues, opening schools in the midst of a generational pandemic has been politicized to the point that the question of whether it is safe to do so has been obscured and confounded. However, this question still deserves to be examined based on evidence.
What We Know About Kids and COVID-19
Some arguments for returning to in-person education have focused on the fact that children and young adults are less susceptible to severe disease. In some cases, people have stated that children cannot be infected, pointing to countries that have resumed in-person education with no associated outbreaks. However, those countries had extremely low community transmission and robust testing and surveillance.
The notion that children are immune or resistant to SARS-CoV-2 is demonstrably untrue: children can be infected, they can become sick, and, in rare cases, they can die. Children can also transmit the virus to others, especially if they are in prolonged proximity to them. A Georgia sleepaway camp was the site of at least 260 cases among mostly children and teenagers, some as young as 6 years old. Children have been shown to shed infectious virus in their nasal secretions and have viral loads comparable to adults. Children can unquestionably be infected with SARS-CoV-2 and spread it to others.
The more data emerges, the more it appears that both primary and secondary schools and universities alike are conducive environments for super-spreading. Mitigating these risks depends heavily on individual schools' ability to enforce reduction measures. So far, the evidence demonstrates that in most cases, schools are unable to adequately protect students or staff. A school superintendent from a small district in Arizona recently described an outbreak that occurred among staff prior to in-person classes resuming. Schools that have opened so far have almost immediately reported new clusters of cases among students or staff.
This is because it is impossible to completely eliminate risk even with the most thoughtful mitigation measures when community transmission is high. Risk can be reduced, but the greater the likelihood that someone will be exposed in the community, the greater the risk they might pass the virus to others on campus or in the classroom.
There are still many unknowns about SARS-CoV-2 transmission, but some environments are known risks for virus transmission: enclosed spaces with crowds of people in close proximity over extended durations. Transmission is thought to occur predominantly through inhaled aerosols or droplets containing SARS-CoV-2, which are produced through common school activities such as breathing, speaking, or singing. Masks reduce but do not eliminate the production of these aerosols. Implementing universal mask-wearing and physical distancing guidelines will furthermore be extraordinarily challenging for very young children.
Smaller particle aerosols can remain suspended in the air and accumulate over time. In an enclosed space where people are gathering, such as a classroom, this renders risk mitigation measures such as physical distancing and masks ineffective. Many classrooms at all levels of education are not conducive to improving ventilation through low-cost measures such as opening windows, much less installing costly air filtration systems.
As a risk reduction measure, ventilation greatly depends on factors like window placement, window type, room size, room occupancy, building HVAC systems, and overall airflow. There isn't much hard data on the specific effects of ventilation on virus transmission, and the models that support ventilation rely on assumptions based on scant experimental evidence that doesn't account for virologic parameters.
There is also no data about how effective air filtration or UV systems would be for SARS-CoV-2 transmission risk reduction, so it's hard to say if this would result in a meaningful risk reduction or not. We don't have enough data outside of a hospital setting to support that ventilation and/or filtration would significantly reduce risk, and it's impractical (and most likely impossible in most schools) to implement hospital ventilation systems, which would likely require massive remodeling of existing HVAC infrastructure. In a close contact situation, the risk reduction might be minimal anyway since it's difficult to avoid exposure to respiratory aerosols and droplets a person is exhaling.
You'd need to get very low rates in the local community to open safely in person regardless of other risk reduction measures, and this would need to be complemented by robust testing and contact tracing capacity.
Efforts to resume in-person education depend heavily on school health and safety plans, which often rely on self-reporting of symptoms due to insufficient testing capacity. Self-reporting is notoriously unreliable, and furthermore, SARS-CoV-2 can be readily transmitted by pre-symptomatic individuals who may be unaware that they are sick, making testing an essential component of any such plan. Primary and secondary schools are faced with limited access to testing and no funds to support it. Even in institutions that include a testing component in their reopening plans, this is still too infrequent to support the full student body returning to campus.
Economic Conflicts of Interest
Rebecca Harrison, a PhD candidate at Cornell University serving on the campus reopening committee, is concerned that her institution's plan places too much faith in testing capacity and is over-reliant on untested models. Harrison says that, as a result, students are being implicitly encouraged to return to campus and "very little has been done to actively encourage students who are safe and able to stay home, to actually stay home."
Harrison also is concerned that her institution "presumably hopes to draw students back from the safety of their parents' basements to (re)join the residential campus experience ... and drive revenue." This is a legitimate concern. Some schools may be actively thwarting safety plans in place to protect students based on financial incentives. Student athletes at Colorado State have alleged that football coaches told them not to report COVID-19 symptoms and are manipulating contact tracing reports.
Public primary and secondary schools are not dependent on student athletics for revenue, but nonetheless are susceptible to state and federal policies that tie reopening to budgets. If schools are forced to make decisions based on a balance sheet, rather than the health and safety of students, teachers, and staff, they will implement health and safety plans that are inadequate. Schools will become ground zero for new clusters of cases.
Looking Ahead: When Will Schools Be Able to Open Again?
One crucial measure is the percent positivity rate in the local community, the number of positive tests based on all the tests that are done. Some states, like California, have implemented policies guiding the reopening of schools that depend in part on a local community's percent positivity rate falling under 8 percent, among other benchmarks including the rate of new daily cases. Currently, statewide, test positivity is below 7%, with an average of 3 new daily cases per 1000 people per day. However, the California department of health acknowledges that new cases per day are underreported. There are 6.3 million students in the California public school system, suggesting that at any given time, there could be nearly 20,000 students who might be contagious, without accounting for presymptomatic teachers and staff. In the classroom environment, just one of those positive cases could spread the virus to many people in one day despite masks, distancing, and ventilation.
You'd need to get very low rates in the local community to open safely in person regardless of other risk reduction measures, and this would need to be complemented by robust testing and contact tracing capacity. Only with rapid identification and isolation of new cases, followed by contact tracing and quarantine, can we break chains of transmission and prevent further spread in the school and the larger community.
None of these safety concerns diminish the many harms associated with the sudden and haphazard way remote learning has been implemented. Online education has not been effective in many cases and is difficult to implement equitably. Young children, in particular, are deprived of the essential social and intellectual development they would normally get in a classroom with teachers and their peers. Parents of young children are equally unprepared and unable to provide full-time instruction. Our federal leadership's catastrophic failure to contain the pandemic like other countries has put us in this terrible position, where we must choose between learning or spreading a deadly pathogen.
Blame aside, parents, educators, and administrators must decide whether to resume in-person classes this fall. Those decisions should be based on evidence, not on politics or economics. The data clearly shows that community transmission is out of control throughout most of the country. Thus, we ignore the risk of school outbreaks at our peril.
[Editor's Note: Here's the other essay in the Back to School series: 5 Key Questions to Consider Before Sending Your Child Back to School.]
In the 1966 movie "Fantastic Voyage," actress Raquel Welch and her submarine were shrunk to the size of a cell in order to eliminate a blood clot in a scientist's brain. Now, 55 years later, the scenario is becoming closer to reality.
California-based startup Bionaut Labs has developed a nanobot about the size of a grain of rice that's designed to transport medication to the exact location in the body where it's needed. If you think about it, the conventional way to deliver medicine makes little sense: A painkiller affects the entire body instead of just the arm that's hurting, and chemotherapy is flushed through all the veins instead of precisely targeting the tumor.
"Chemotherapy is delivered systemically," Bionaut-founder and CEO Michael Shpigelmacher says. "Often only a small percentage arrives at the location where it is actually needed."
But what if it was possible to send a tiny robot through the body to attack a tumor or deliver a drug at exactly the right location?
Several startups and academic institutes worldwide are working to develop such a solution but Bionaut Labs seems the furthest along in advancing its invention. "You can think of the Bionaut as a tiny screw that moves through the veins as if steered by an invisible screwdriver until it arrives at the tumor," Shpigelmacher explains. Via Zoom, he shares the screen of an X-ray machine in his Culver City lab to demonstrate how the half-transparent, yellowish device winds its way along the spine in the body. The nanobot contains a tiny but powerful magnet. The "invisible screwdriver" is an external magnetic field that rotates that magnet inside the device and gets it to move and change directions.
The current model has a diameter of less than a millimeter. Shpigelmacher's engineers could build the miniature vehicle even smaller but the current size has the advantage of being big enough to see with bare eyes. It can also deliver more medicine than a tinier version. In the Zoom demonstration, the micorobot is injected into the spine, not unlike an epidural, and pulled along the spine through an outside magnet until the Bionaut reaches the brainstem. Depending which organ it needs to reach, it could be inserted elsewhere, for instance through a catheter.
"The hope is that we can develop a vehicle to transport medication deep into the body," says Max Planck scientist Tian Qiu.
Imagine moving a screw through a steak with a magnet — that's essentially how the device works. But of course, the Bionaut is considerably different from an ordinary screw: "At the right location, we give a magnetic signal, and it unloads its medicine package," Shpigelmacher says.
To start, Bionaut Labs wants to use its device to treat Parkinson's disease and brain stem gliomas, a type of cancer that largely affects children and teenagers. About 300 to 400 young people a year are diagnosed with this type of tumor. Radiation and brain surgery risk damaging sensitive brain tissue, and chemotherapy often doesn't work. Most children with these tumors live less than 18 months. A nanobot delivering targeted chemotherapy could be a gamechanger. "These patients really don't have any other hope," Shpigelmacher says.
Of course, the main challenge of the developing such a device is guaranteeing that it's safe. Because tissue is so sensitive, any mistake could risk disastrous results. In recent years, Bionaut has tested its technology in dozens of healthy sheep and pigs with no major adverse effects. Sheep make a good stand-in for humans because their brains and spines are similar to ours.
The Bionaut device is about the size of a grain of rice.
Bionaut Labs
"As the Bionaut moves through brain tissue, it creates a transient track that heals within a few weeks," Shpigelmacher says. The company is hoping to be the first to test a nanobot in humans. In December 2022, it announced that a recent round of funding drew $43.2 million, for a total of 63.2 million, enabling more research and, if all goes smoothly, human clinical trials by early next year.
Once the technique has been perfected, further applications could include addressing other kinds of brain disorders that are considered incurable now, such as Alzheimer's or Huntington's disease. "Microrobots could serve as a bridgehead, opening the gateway to the brain and facilitating precise access of deep brain structure – either to deliver medication, take cell samples or stimulate specific brain regions," Shpigelmacher says.
Robot-assisted hybrid surgery with artificial intelligence is already used in state-of-the-art surgery centers, and many medical experts believe that nanorobotics will be the instrument of the future. In 2016, three scientists were awarded the Nobel Prize in Chemistry for their development of "the world's smallest machines," nano "elevators" and minuscule motors. Since then, the scientific experiments have progressed to the point where applicable devices are moving closer to actually being implemented.
Bionaut's technology was initially developed by a research team lead by Peer Fischer, head of the independent Micro Nano and Molecular Systems Lab at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany. Fischer is considered a pioneer in the research of nano systems, which he began at Harvard University more than a decade ago. He and his team are advising Bionaut Labs and have licensed their technology to the company.
"The hope is that we can develop a vehicle to transport medication deep into the body," says Max Planck scientist Tian Qiu, who leads the cooperation with Bionaut Labs. He agrees with Shpigelmacher that the Bionaut's size is perfect for transporting medication loads and is researching potential applications for even smaller nanorobots, especially in the eye, where the tissue is extremely sensitive. "Nanorobots can sneak through very fine tissue without causing damage."
In "Fantastic Voyage," Raquel Welch's adventures inside the body of a dissident scientist let her swim through his veins into his brain, but her shrunken miniature submarine is attacked by antibodies; she has to flee through the nerves into the scientist's eye where she escapes into freedom on a tear drop. In reality, the exit in the lab is much more mundane. The Bionaut simply leaves the body through the same port where it entered. But apart from the dramatization, the "Fantastic Voyage" was almost prophetic, or, as Shpigelmacher says, "Science fiction becomes science reality."
This article was first published by Leaps.org on April 12, 2021.
How the Human Brain Project Built a Mind of its Own
In 2009, neuroscientist Henry Markram gave an ambitious TED talk. “Our mission is to build a detailed, realistic computer model of the human brain,” he said, naming three reasons for this unmatched feat of engineering. One was because understanding the human brain was essential to get along in society. Another was because experimenting on animal brains could only get scientists so far in understanding the human ones. Third, medicines for mental disorders weren’t good enough. “There are two billion people on the planet that are affected by mental disorders, and the drugs that are used today are largely empirical,” Markram said. “I think that we can come up with very concrete solutions on how to treat disorders.”
Markram's arguments were very persuasive. In 2013, the European Commission launched the Human Brain Project, or HBP, as part of its Future and Emerging Technologies program. Viewed as Europe’s chance to try to win the “brain race” between the U.S., China, Japan, and other countries, the project received about a billion euros in funding with the goal to simulate the entire human brain on a supercomputer, or in silico, by 2023.
Now, after 10 years of dedicated neuroscience research, the HBP is coming to an end. As its many critics warned, it did not manage to build an entire human brain in silico. Instead, it achieved a multifaceted array of different goals, some of them unexpected.
Scholars have found that the project did help advance neuroscience more than some detractors initially expected, specifically in the area of brain simulations and virtual models. Using an interdisciplinary approach of combining technology, such as AI and digital simulations, with neuroscience, the HBP worked to gain a deeper understanding of the human brain’s complicated structure and functions, which in some cases led to novel treatments for brain disorders. Lastly, through online platforms, the HBP spearheaded a previously unmatched level of global neuroscience collaborations.
Simulating a human brain stirs up controversy
Right from the start, the project was plagued with controversy and condemnation. One of its prominent critics was Yves Fregnac, a professor in cognitive science at the Polytechnic Institute of Paris and research director at the French National Centre for Scientific Research. Fregnac argued in numerous articles that the HBP was overfunded based on proposals with unrealistic goals. “This new way of over-selling scientific targets, deeply aligned with what modern society expects from mega-sciences in the broad sense (big investment, big return), has been observed on several occasions in different scientific sub-fields,” he wrote in one of his articles, “before invading the field of brain sciences and neuromarketing.”
"A human brain model can simulate an experiment a million times for many different conditions, but the actual human experiment can be performed only once or a few times," said Viktor Jirsa, a professor at Aix-Marseille University.
Responding to such critiques, the HBP worked to restructure the effort in its early days with new leadership, organization, and goals that were more flexible and attainable. “The HBP got a more versatile, pluralistic approach,” said Viktor Jirsa, a professor at Aix-Marseille University and one of the HBP lead scientists. He believes that these changes fixed at least some of HBP’s issues. “The project has been on a very productive and scientifically fruitful course since then.”
After restructuring, the HBP became a European hub on brain research, with hundreds of scientists joining its growing network. The HBP created projects focused on various brain topics, from consciousness to neurodegenerative diseases. HBP scientists worked on complex subjects, such as mapping out the brain, combining neuroscience and robotics, and experimenting with neuromorphic computing, a computational technique inspired by the human brain structure and function—to name just a few.
Simulations advance knowledge and treatment options
In 2013, it seemed that bringing neuroscience into a digital age would be farfetched, but research within the HBP has made this achievable. The virtual maps and simulations various HBP teams create through brain imaging data make it easier for neuroscientists to understand brain developments and functions. The teams publish these models on the HBP’s EBRAINS online platform—one of the first to offer access to such data to neuroscientists worldwide via an open-source online site. “This digital infrastructure is backed by high-performance computers, with large datasets and various computational tools,” said Lucy Xiaolu Wang, an assistant professor in the Resource Economics Department at the University of Massachusetts Amherst, who studies the economics of the HBP. That means it can be used in place of many different types of human experimentation.
Jirsa’s team is one of many within the project that works on virtual brain models and brain simulations. Compiling patient data, Jirsa and his team can create digital simulations of different brain activities—and repeat these experiments many times, which isn’t often possible in surgeries on real brains. “A human brain model can simulate an experiment a million times for many different conditions,” Jirsa explained, “but the actual human experiment can be performed only once or a few times.” Using simulations also saves scientists and doctors time and money when looking at ways to diagnose and treat patients with brain disorders.
Compiling patient data, scientists can create digital simulations of different brain activities—and repeat these experiments many times.
The Human Brain Project
Simulations can help scientists get a full picture that otherwise is unattainable. “Another benefit is data completion,” added Jirsa, “in which incomplete data can be complemented by the model. In clinical settings, we can often measure only certain brain areas, but when linked to the brain model, we can enlarge the range of accessible brain regions and make better diagnostic predictions.”
With time, Jirsa’s team was able to move into patient-specific simulations. “We advanced from generic brain models to the ability to use a specific patient’s brain data, from measurements like MRI and others, to create individualized predictive models and simulations,” Jirsa explained. He and his team are working on this personalization technique to treat patients with epilepsy. According to the World Health Organization, about 50 million people worldwide suffer from epilepsy, a disorder that causes recurring seizures. While some epilepsy causes are known others remain an enigma, and many are hard to treat. For some patients whose epilepsy doesn’t respond to medications, removing part of the brain where seizures occur may be the only option. Understanding where in the patients’ brains seizures arise can give scientists a better idea of how to treat them and whether to use surgery versus medications.
“We apply such personalized models…to precisely identify where in a patient’s brain seizures emerge,” Jirsa explained. “This guides individual surgery decisions for patients for which surgery is the only treatment option.” He credits the HBP for the opportunity to develop this novel approach. “The personalization of our epilepsy models was only made possible by the Human Brain Project, in which all the necessary tools have been developed. Without the HBP, the technology would not be in clinical trials today.”
Personalized simulations can significantly advance treatments, predict the outcome of specific medical procedures and optimize them before actually treating patients. Jirsa is watching this happen firsthand in his ongoing research. “Our technology for creating personalized brain models is now used in a large clinical trial for epilepsy, funded by the French state, where we collaborate with clinicians in hospitals,” he explained. “We have also founded a spinoff company called VB Tech (Virtual Brain Technologies) to commercialize our personalized brain model technology and make it available to all patients.”
The Human Brain Project created a level of interconnectedness within the neuroscience research community that never existed before—a network not unlike the brain’s own.
Other experts believe it’s too soon to tell whether brain simulations could change epilepsy treatments. “The life cycle of developing treatments applicable to patients often runs over a decade,” Wang stated. “It is still too early to draw a clear link between HBP’s various project areas with patient care.” However, she admits that some studies built on the HBP-collected knowledge are already showing promise. “Researchers have used neuroscientific atlases and computational tools to develop activity-specific stimulation programs that enabled paraplegic patients to move again in a small-size clinical trial,” Wang said. Another intriguing study looked at simulations of Alzheimer’s in the brain to understand how it evolves over time.
Some challenges remain hard to overcome even with computer simulations. “The major challenge has always been the parameter explosion, which means that many different model parameters can lead to the same result,” Jirsa explained. An example of this parameter explosion could be two different types of neurodegenerative conditions, such as Parkinson’s and Huntington’s diseases. Both afflict the same area of the brain, the basal ganglia, which can affect movement, but are caused by two different underlying mechanisms. “We face the same situation in the living brain, in which a large range of diverse mechanisms can produce the same behavior,” Jirsa said. The simulations still have to overcome the same challenge.
Understanding where in the patients’ brains seizures arise can give scientists a better idea of how to treat them and whether to use surgery versus medications.
The Human Brain Project
A network not unlike the brain’s own
Though the HBP will be closing this year, its legacy continues in various studies, spin-off companies, and its online platform, EBRAINS. “The HBP is one of the earliest brain initiatives in the world, and the 10-year long-term goal has united many researchers to collaborate on brain sciences with advanced computational tools,” Wang said. “Beyond the many research articles and projects collaborated on during the HBP, the online neuroscience research infrastructure EBRAINS will be left as a legacy even after the project ends.”
Those who worked within the HBP see the end of this project as the next step in neuroscience research. “Neuroscience has come closer to very meaningful applications through the systematic link with new digital technologies and collaborative work,” Jirsa stated. “In that way, the project really had a pioneering role.” It also created a level of interconnectedness within the neuroscience research community that never existed before—a network not unlike the brain’s own. “Interconnectedness is an important advance and prerequisite for progress,” Jirsa said. “The neuroscience community has in the past been rather fragmented and this has dramatically changed in recent years thanks to the Human Brain Project.”
According to its website, by 2023 HBP’s network counted over 500 scientists from over 123 institutions and 16 different countries, creating one of the largest multi-national research groups in the world. Even though the project hasn’t produced the in-silico brain as Markram envisioned it, the HBP created a communal mind with immense potential. “It has challenged us to think beyond the boundaries of our own laboratories,” Jirsa said, “and enabled us to go much further together than we could have ever conceived going by ourselves.”