Published in Science Advances, the paper explores the ongoing “replication crisis” in which researchers have discovered that many findings in the fields of social sciences and medicine don’t hold up when other researchers try to repeat the experiments.

The paper reveals that findings from studies that cannot be verified when the experiments are repeated have a bigger influence over time. The unreliable research tends to be cited as if the results were true long after the publication failed to replicate.

“We also know that experts can predict well which papers will be replicated,” write the authors Marta Serra-Garcia, assistant professor of economics and strategy at the Rady School and Uri Gneezy, professor of behavioral economics also at the Rady School. “Given this prediction, we ask ‘why are non-replicable papers accepted for publication in the first place?'”

Their possible answer is that review teams of academic journals face a trade-off. When the results are more “interesting,” they apply lower standards regarding their reproducibility.

The link between interesting findings and nonreplicable research also can explain why it is cited at a much higher rate — the authors found that papers that successfully replicate are cited 153 times less than those that failed.

“Interesting or appealing findings are also covered more by media or shared on platforms like Twitter, generating a lot of attention, but that does not make them true,” Gneezy said.

Serra-Garcia and Gneezy analyzed data from three influential replication projects which tried to systematically replicate the findings in top psychology, economic and general science journals (Nature and Science). In psychology, only 39 percent of the 100 experiments successfully replicated. In economics, 61 percent of the 18 studies replicated as did 62 percent of the 21 studies published in Nature/Science.

With the findings from these three replication projects, the authors used Google Scholar to test whether papers that failed to replicate are cited significantly more often than those that were successfully replicated, both before and after the replication projects were published. The largest gap was in papers published in Nature/Science: non-replicable papers were cited 300 times more than replicable ones.

When the authors took into account several characteristics of the studies replicated — such as the number of authors, the rate of male authors, the details of the experiment (location, language and online implementation) and the field in which the paper was published — the relationship between replicability and citations was unchanged.

They also show the impact of such citations grows over time. Yearly citation counts reveal a pronounced gap between papers that replicated and those that did not. On average, papers that failed to replicate are cited 16 times more per year. This gap remains even after the replication project is published.

“Remarkably, only 12 percent of post-replication citations of non-replicable findings acknowledge the replication failure,” the authors write.

The influence of an inaccurate paper published in a prestigious journal can have repercussions for decades. For example, the study Andrew Wakefield published in The Lancet in 1998 turned tens of thousands of parents around the world against the measles, mumps and rubella vaccine because of an implied link between vaccinations and autism. The incorrect findings were retracted by The Lancet 12 years later, but the claims that autism is linked to vaccines continue.

The authors added that journals may feel pressure to publish interesting findings, and so do academics. For example, in promotion decisions, most academic institutions use citations as an important metric in the decision of whether to promote a faculty member.

This may be the source of the “replication crisis,” first discovered the early 2010s.

“We hope our research encourages readers to be cautious if they read something that is interesting and appealing,” Serra-Garcia said. “Whenever researchers cite work that is more interesting or has been cited a lot, we hope they will check if replication data is available and what those findings suggest.”

Gneezy added, “We care about the field and producing quality research and we want to it to be true.”

The new study, published in the journal Global Change Biology, builds upon the team’s prior work observing how wildlife in the Santa Cruz Mountains respond to human disturbance. Local observations, for example, have shown that species like pumas and bobcats are less likely to be active in areas where humans are present, while deer and wood rats become bolder and more active. But it’s difficult to generalize findings like these across larger geographic areas because human-wildlife interactions are often regionally unique.

So, to get a continent-wide sense for which species of mammals might be best equipped to live alongside humans, the team combined their local camera trap data with that of researchers throughout the U.S., Canada, and Mexico. This allowed them to track 24 species across 61 regionally diverse camera trap projects to see which larger trends emerged.

“We’ve been very interested for a long time in how human disturbance influences wildlife, and we thought it would be interesting to see how wildlife in general are responding to similar anthropogenic pressures across North America,” said Chris Wilmers, an environmental studies professor and director of the Santa Cruz Puma Project, who is the paper’s senior author alongside lead author Justin Suraci.

The team was especially interested in understanding how mammals respond to different types of human disturbance and whether these responses were related to species’ traits, like body size, diet, and the number of young they have. Overall, the paper found that 33 percent of mammal species responded negatively to humans, meaning they were less likely to occur in places with higher disturbance and were less active when present, while 58 percent of species were actually positively associated with disturbance.

To get a closer look at these trends, the team broke their results down by two different types of human disturbance. One was the footprint of human development: the things that people build, like roads, houses, and agricultural fields. Another was the mere presence of people, including activities like recreation and hunting, since fear of humans can change an animal’s behavior and use of space.

In comparing continent-wide data from camera trap locations with varying levels of human development, researchers found that grizzly bears, lynx, wolves, and wolverines were generally less likely to be found in more developed areas and were less active when they did visit. Moose and martens were also less active in areas with a higher development footprint.

Meanwhile, raccoons and white-tailed deer were actually more likely to hang out in more developed areas and were more active in these spaces. Elk, mule deer, striped skunks, red foxes, bobcats, coyotes, and pumas weren’t more likely to be found in developed landscapes, but they did tend to be more active in these areas.

Some of the species that frequent more developed areas may actually benefit from living in these places, but the study’s lead author, Justin Suraci, a lead scientist at Conservation Science Partners and former postdoctoral researcher at UC Santa Cruz, says that’s not necessarily the case. While raccoons can thrive in developed areas by finding food in our garbage cans and avoiding predators, higher levels of puma activity in these same places could mean something very different.

“It’s not because these developed areas are really good for puma activity,” Suraci said. “It’s probably because the camera traps happened to be set in the one pathway that the poor puma can use when it’s navigating its way through an otherwise very heavily developed landscape.”

In other words, some animals in the study may be increasingly active or present on cameras near human development simply because there’s such little remaining natural habitat.

Still, there were certain traits that emerged across species as clear advantages for making a living within the footprint of development. Overall, mammals that were smaller and faster-reproducing, with generalist diets, were the most positively associated with development. Researchers expected they might find similar results in comparing camera trap data by levels of human presence, but in fact, both positive and negative responses to human presence were observed for species across the spectrum of body sizes and diets.

Elk were less likely to stick around in places frequented by humans, and moose, mountain goats, and wolverines were less active in these habitats. On the other hand, bighorn sheep, black bears, and wolverines were more likely to be found in areas frequented by humans, while mule deer, bobcats, grey foxes, pumas, and wolves were more active.

One trend that may be influencing these findings is the growth of outdoor recreation, which increases levels of human presence in otherwise remote and wild landscapes. The study’s results may indicate that most mammals are willing to tolerate some level of human recreation in order to remain in high quality habitats, and they could instead be increasing their nocturnal activity in order to avoid humans. Some animals may even take advantage of hiking trails and fire roads as easy movement pathways.

But the study also clearly identified that there’s a limit to how much human impact animals can withstand. Even among species that were either more active or more likely to be present around humans or in developed areas, those effects peaked at low to intermediate levels of human disturbance then began to decline beyond those thresholds. Red foxes were the only animals in the study that seemed to continue to be more active or present at medium to high levels of human disturbance.

Ultimately, most species have both something to lose and something to gain from being around humans, and understanding the cutoff at which the costs outweigh the benefits for each species will be important to maintaining suitable habitats that support diversity in mammal populations for the future. Suraci says this may prove to be the new paper’s most important contribution.

“From a management perspective, I think the thresholds that we’ve started to identify are going to be really relevant,” he said. “This can help us get a sense of how much available habitat is actually out there for recolonizing or reintroduced species and hopefully allow us to more effectively coexist with wildlife in human-dominated landscapes.”

But at least parts of the show could go on during the pandemic — with some significant changes.

“For paleontologists, going into the field to look for fossils is where data collection begins, but it does not end there,” said Christian Sidor, a University of Washington professor of biology and curator of vertebrate paleontology at the UW’s Burke Museum of Natural History & Culture. “After you collect fossils, you have to bring them to the laboratory, clean them off and see what you’ve found.”

Among other adaptations during the pandemic, Sidor and his UW colleagues have spent more time cleaning, preparing and analyzing fossils excavated before the pandemic, as well as managing new pandemic-related struggles — such as a misplaced shipment of irreplaceable specimens.

For Sidor’s team, a recent triumph came from an analysis — led by UW postdoctoral researcher Bryan Gee — of fossils of Micropholis stowi, a salamander-sized amphibian that lived in the Early Triassic, shortly after Earth’s largest mass extinction approximately 252 million years ago, at the end of the Permian Period. Micropholis is a temnospondyl, a group of extinct amphibians known from fossil deposits around the globe. In a paper published May 21 in the Journal of Vertebrate Paleontology, Gee and Sidor report on the first occurrence of Micropholis in ancient Antarctica.

“Previously, Micropholis was only known from South African specimens,” said Gee. “That isolation was considered fairly typical for amphibians in the Southern Hemisphere during the Early Triassic. Each region — South Africa, Madagascar, Antarctica, Australia — will have its own set of amphibian species. Now, we’re seeing that Micropholis was more widespread than previously recognized.”

Out of more than 30 Early Triassic amphibians in the Southern Hemisphere, Micropholis is now only the second found in more than one region, according to Gee. That is surprising given Earth’s geography. In the Early Triassic, most of Earth’s continents were connected as a part of a single, large landmass, Pangea. Places like South Africa and Antarctica were not as far apart as they are today, and may have had similar climates. Some scientists theorize that these closely placed regions could harbor different amphibian species as a consequence of the end-Permian mass extinction.

“It had been proposed that there were only small populations of survivors and low movement of species in the Early Triassic, which could have explained these regional differences,” said Gee.

Finding Micropholis in two regions may indicate that this species was a “generalist” — adaptable to many types of environments — and could easily spread after the mass extinction.

Alternatively, it’s possible that many other amphibians actually lived in multiple regions, like Micropholis, but paleontologists haven’t found evidence yet. While some Southern Hemisphere regions like South Africa have been well sampled, others have not — like Antarctica, which in the Early Triassic was relatively temperate, but is today largely covered by ice sheets.

Sidor’s team collected skulls and other fragile body parts from four individuals of Micropholis during a 2017-2018 collection trip to the Transantarctic Mountains. In 2019, Gee agreed to come to the UW to lead the analysis of amphibian fossils from that trip after completing his doctoral degree at the University of Toronto. He completed his degree early in the pandemic and moved to Seattle during the second wave of COVID-19.

With social distancing measures in place on campus, Sidor delivered the fossils and a microscope to Gee’s home, where he analyzed the specimens in his living room.

“Having access to the microscope was really the most essential piece of equipment, to be able to identify all the small-scale anatomical features that we need to definitively prove these were Micropholis fossils,” said Gee.

On the same trip, Sidor’s team collected another rare find: a well-preserved skull of a therocephalian, a group of extinct mammal relatives that lived in the Permian and Triassic periods. Therocephalians were a widespread group of both herbivores and carnivores.

“But the Antarctic record for these animals is very poor,” said Sidor. “So this was a rare find.”

It was a rare find that nearly went extinct again. Sidor shipped the therocephalian skull in October 2019 to Chicago’s Field Museum, where it was cleaned and prepped by his longtime colleague Akiko Shinya.

“Not being able to travel to museums to do research, we’ve been shipping fossils to each other — which we don’t like to do, but sometimes we have to in order to keep the work going,” said Sidor.

In early April, Shinya shipped the finished specimens overnight back to Sidor in Seattle, but the package did not show up at the projected time. As Sidor recounted on Twitter, the skull was apparently lost in a transfer facility in Indiana — he feared for good. After several days, the package was found, and was promptly transported to Seattle and delivered safely to the UW.

“I was so relieved,” said Sidor. “When I thought it was lost, I had been thinking about the insurance forms. How do you put a dollar value on a specimen that you needed an LC-130 Hercules to collect?”

The skull is undergoing analysis at the UW. As for the Antarctic Micropholis specimens, they’ll soon receive a new home. Later this year, they’ll go on display at the Burke Museum.

“Itch is a significant clinical problem, often caused by underlying medical conditions in the skin, liver, or kidney. Due to our limited understanding of itch mechanisms, we don’t have effective treatment for the majority of patients,” said Liang Han, an assistant professor in the Georgia Institute of Technology’s School of Biological Sciences who is also a researcher in the Parker H. Petit Institute for Bioengineering and Bioscience.

Until recently, neuroscientists considered the mechanisms of skin itch the same. But Han and her research team recently uncovered differences in itch in non-hairy versus hairy areas of the skin, opening new areas for research.

Their research, published April 13 in the journal PNAS (Proceedings of the National Academy of Sciences), could open new, more effective treatments for patients suffering from persistent skin itching.

Itch Origins More Than Skin Deep

According to researchers, there are two different types of stimuli from the nervous system that trigger the itch sensation through sensory nerves in the skin ? chemical and mechanical. In their study, Han and her team identified a specific neuron population that controls itching in ‘glabrous’ skin ?the smoother, tougher skin that’s found on the palms of hands and feet soles.

Itching in those areas poses greater difficulty for sufferers and is surprisingly common. In the U.S., there are an estimated 200,000 cases a year of dyshidrosis, a skin condition causing itchy blisters to develop only on the palm and soles. Another chronic skin condition, palmoplantar pustulosis (a type of psoriasis that causes inflamed, scaly skin and intense itch on the palms and soles), affects as many as 1.6 million people in the U.S. each year.

“That’s actually one of the most debilitating places (to get an itch),” said first author Haley R. Steele, a graduate student in the School of Biological Sciences. “If your hands are itchy, it’s hard to grasp things, and if it’s your feet, it can be hard to walk. If there’s an itch on your arm, you can still type. You’ll be distracted, but you’ll be OK. But if it’s your hands and feet, it’s harder to do everyday things.”

Ability to Block, Activate Itch-causing Neurons in Lab Mice

Since many biological mechanisms underlying itch — such as receptors and nerve pathways — are similar in mice and people, most itch studies rely on mice testing. Using mice in their lab, Georgia Tech researchers were able to activate or block these neurons.

The research shows, for the first time, “the actual neurons that send itch are different populations. Neurons that are in hairy skin that do not sense itch in glabrous skins are one population, and another senses itch in glabrous skins.”

Why has an explanation so far eluded science? “I think one reason is because most of the people in the field kind of assumed it was the same mechanism that’s controlling the sensation. It’s technically challenging. It’s more difficult than working on hairy skin,” Han said.

To overcome this technical hurdle, the team used a new investigative procedure, or assay, modeled after human allergic contact dermatitis, Steele said.

The previous method would have involved injecting itch-causing chemicals into mice skin, but most of a mouse’s skin is covered with hair. The team had to focus on the smooth glabrous skin on tiny mice hands and feet. Using genetically modified mice also helped identify the right sensory neurons responsible for glabrous skin itches.

“We activated a particular set of neurons that causes itch, and we saw that biting behavior again modeled,” said Steele, referring to how mice usually deal with itchy skin.

One set of study mice was given a chemical to specifically kill an entire line of neurons. Focusing on three previously known neuron mechanisms related to itch sensation found in hairy skin, they found that two of the neurons, MrgprA3+ and MrgprD+, did not play important roles in non-hairy skin itch, but the third neuron, MrgprC11+, did. Removing it reduced both acute and chronic itching in the soles and palms of test mice.

Potential to Drive New Treatments for Chronic Itch

Han’s team hopes that the research leads to treatments that will turn off those itch-inducing neurons, perhaps by blocking them in human skin.

“To date, most treatments for skin itch do not discriminate between hairy and glabrous skin except for potential medication potency due to the increased skin thickness in glabrous skin,” observed Ron Feldman, assistant professor in the Department of Dermatology in the Emory University School of Medicine. Georgia Tech’s findings “provide a rationale for developing therapies targeting chronic itching of the hands and feet that, if left untreated, can greatly affect patient quality of life,” he concluded.

What’s next for Han and her team? “We would like to investigate how these neurons transmit information to the spinal cord and brain,” said Han, who also wants to investigate the mechanisms of chronic itch conditions that mainly affect glabrous skin such as cholestatic itch, or itch due to reduced or blocked bile flow often seen in liver and biliary system diseases.

“I joined this lab because I love working with Liang Han,” added Steele, who selected glabrous skin itch research for her Ph.D. “because it was the most technically challenging and had the greatest potential for being really interesting and significant to the field.”

However, a new brain imaging study by Yale scientists shows that infants as young as three months are already enlisting the hippocampus to recognize and learn patterns. The findings were published May 21 in the journal Current Biology.

“A fundamental mystery about human nature is that we remember almost nothing from birth through early childhood, yet we learn so much critical information during that time — our first language, how to walk, objects and foods, and social bonds,” said Nick Turk-Browne, a professor of psychology at Yale and senior author of the paper.

For the new study, the Yale team used a new functional magnetic resonance imaging (fMRI) technology to capture activity in the hippocampus in 17 babies, aged three months to two years old, as they were presented two sets of images on a screen. One set of images appeared as a structured sequence containing hidden patterns that could be learned. In the other, images appeared in a random order that offered no opportunity for learning. After the babies were shown these two sets of images several times, the hippocampus responded more strongly to the structured image set than to the random image set.

What might be happening, Turk-Browne said, is that as a baby gains experience in the world, their brain searches for general patterns that help them understand and predict the surrounding environment. This happens even though the brain is not equipped to permanently store each individual experience about a specific moment in space and time — the hallmark of episodic memory that is also lost in adult amnesia.

The strategy makes sense because learning general knowledge — such as patterns of sounds that make up the words in a language — may be more important to a baby than remembering specific details, such as a single incident in which a particular word was uttered.

The size of the hippocampus doubles in the first two years of life and eventually develops connections necessary to store episodic memories, Turk-Browne said.

“As these circuit changes occur, we eventually obtain the ability to store memories,” he said. “But our research shows that even if we can’t remember infant experiences later on in life, they are being recorded nevertheless in a way that allows us to learn from them.”

Yale’s Cameron Ellis is first author of the study, and this research was included in his recently completed and award-winning PhD dissertation.

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Organic pollutants such as pharmaceuticals, pesticides, and hormones — even at nanoscale concentrations — contaminate drinking water in a way that poses significant risks to humans, animals, and the environment. In particular, the steroid hormones estrone, estradiol, progesterone, and testosterone can cause biological damage in humans and wildlife. The European Union has therefore set strict minimum quality standards for safe and clean drinking water, which must also be taken into account in the development of new technologies for water treatment. “The challenge for science is to develop more sensitive methods to target the hormone molecules,” says Professor Andrea Iris Schäfer, Head of the Institute for Advanced Membrane Technology (IAMT) at KIT. The main problem is that steroid hormones are very hard to detect in water. “There is one hormone molecule for every quintillion water molecules. This is an extremely low concentration,” explains the expert.

Detecting — and Removing — Micropollutants

With conventional water treatment technologies, wastewater treatment plants can neither find nor remove micropollutants. Researchers at the IAMT and the KIT Institute of Microstructure Technology (IMT) are therefore working on new methods to not only detect and measure micropollutants, but also remove them. A new, photocatalytic process proves to be promising. The scientists coated a commercially available large-pore polymer membrane with Pd(II)-porphyrin, a palladium-containing, light-sensitive molecule that can absorb visible radiation. Exposure to radiation with simulated sunlight initiates a chemical process that produces so-called singlet oxygen, a highly reactive oxygen species. The singlet oxygen specifically “attacks” the hormone molecules and converts them into potentially safe oxidation products. “It is crucial that we coat the surface of each pore with the photosensitizer molecule, increasing the surface area of attack,” explains Roman Lyubimenko, a scientist at IAMT and IMT.

Significant Reduction of the Estradiol Concentration

The chemical decomposition of steroid hormones and the filtration of other micropollutants can be realized in a single module. With this process, filtering of 60 to 600 liters of water per square meter of membrane is possible in one hour. The scientists were able to reduce the concentration of estradiol, the most biologically active steroid hormone, by 98 percent from 100 to 2 nanograms per liter. “This means that we are already very close to the EU target value of one nanogram per liter,” emphasizes Schäfer. The next goal of the research team is to further optimize the photocatalytic process and transfer it to a larger scale. Open issues are to find out how much light intensity and how much porphyrin will be needed and whether the costly palladium from the platinum group of metals can be replaced by other metals.

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Until now, these differences have often remained unconsidered in catalysis research because it is very difficult to simultaneously obtain information about the chemical reaction itself and about the surface structure of the catalyst. At TU Wien (Vienna), this has now been achieved by combining different microscopic methods: with the help of field electron microscopy and field ion microscopy, it became possible to visualize the oxidation of hydrogen on a single rhodium nanoparticle in real time at nanometer resolution. This revealed surprising effects that will have to be taken into account in the search for better catalysts in the future. The results have now been presented in the scientific journal Science.

The rhythm of chemical reactions

“In certain chemical reactions, a catalyst can periodically switch back and forth between an active and an inactive state,” says Prof. Günter Rupprechter from the Institute of Materials Chemistry at TU Wien. “Self-sustaining chemical oscillations can occur between the two states — the chemist Gerhard Ertl received the Nobel Prize in Chemistry for this discovery in 2007.”

This is also the case with rhodium nanoparticles, which are used as a catalyst for hydrogen oxidation — the basis of every fuel cell. Under certain conditions, the nanoparticles can oscillate between a state in which oxygen molecules dissociate on the surface of the particle and a state in which hydrogen is bound.

Incorporated oxygen changes the surface behaviour

“When a rhodium particle is exposed to an atmosphere of oxygen and hydrogen, the oxygen molecules are split into individual atoms at the rhodium surface. These oxygen atoms can then migrate below the uppermost rhodium layer and accumulate as the subsurface oxygen there,” explains Prof. Yuri Suchorski, the first author of the study.

Through interaction with hydrogen, these stored oxygen atoms can then be brought out again and react with hydrogen atoms. Then, there is again room for more oxygen atoms inside the rhodium particle and the cycle starts again. “This feedback mechanism controls the frequency of the oscillations,” says Yuri Suchorski.

Until now, it was thought that these chemical oscillations always took place synchronously in the same rhythm over the entire nanoparticle. After all, the chemical processes on the different facets of the nanoparticle surface are spatially coupled, as the hydrogen atoms can easily migrate from one facet to the adjacent facets.

However, the results of the research group of Prof. Günther Rupprechter and Prof. Yuri Suchorski show that things are actually much more complex: Under certain conditions, the spatial coupling is lifted and adjacent facets suddenly oscillate with significantly different frequencies — and in some regions of the nanoparticle, these oscillating “chemical waves” do not propagate at all.

“This can be explained on an atomic scale,” says Yuri Suchorski. “Under the influence of oxygen, protruding rows of rhodium atoms can emerge from a smooth surface.” These rows of atoms can then act as a kind of “wave breaker” and hamper the migration of hydrogen atoms from one facet to another — the facets become decoupled.

If this is the case, the individual facets can form oscillations of different frequences. “On different facets, the rhodium atoms are arranged differently on the surface,” says Günther Rupprechter. “That’s why the incorporation of oxygen under the differing facets of the rhodium particle also proceeds at different rates, and so oscillations with different frequencies result on crystallographically different facets.”

A hemisphere tip as a nanoparticle model

The key to unravelling this complex chemical behaviour lays in using a fine rhodium tip as a model for a catalytic nanoparticle. An electric field is applied, and due to the quantum mechanical tunnelling effect, electrons can leave the tip. These electrons are accelerated in the electric field and hit a screen, where a projection image of the tip is then created with a resolution of around 2 nanometers.

In contrast to scanning microscopies, where the surface sites are scanned one after the other, such parallel imaging visualizes all surface atoms simultaneously — otherwise it would not be possible to monitor the synchronization and desynchronization of the oscillations.

The new insights into the interaction of individual facets of a nanoparticle can now lead to more effective catalysts and provide deep atomic insights into mechanisms of non-linear reaction kinetics, pattern formation and spatial coupling.

Research funded by the Austrian Science Fund (FWF) within Project “Spatial-temporal phenomena on surface structure libraries.”

Video: https://www.youtube.com/watch?v=9g7Q4dh_baA

“This shows a possible future that has not yet been fully addressed,” says Fred Adler, PhD, professor of mathematics and biological sciences at the U. “Over the next decade, the severity of COVID-19 may decrease as populations collectively develop immunity.”

The findings suggest that changes in the disease could be driven by adaptations of our immune response rather than by changes in the virus itself. Adler was senior author on the publication with Alexander Beams, first author and graduate student in the Department of Mathematics and the Division of Epidemiology at University of Utah Health, and undergraduate co-author Rebecca Bateman.

Although SARS-CoV-2 (the sometimes-deadly coronavirus causing COVID-19) is the best-known member of that virus family, other seasonal coronaviruses circulate in the human population — and they are much more benign. Some evidence indicates that one of these cold-causing relatives might have once been severe, giving rise to the “Russian flu” pandemic in the late 19th century. The parallels led the U of U scientists to wonder whether the severity of SARS-CoV-2 could similarly lessen over time.

To test the idea, they built mathematical models incorporating evidence on the body’s immune response to SARS-CoV-2 based on the following data from the current pandemic.

• There is likely a dose response between virus exposure and disease severity.
  • A person exposed to a small dose of virus will be more likely to get a mild case of COVID-19 and shed small amounts of virus.
  • By contrast, adults exposed to a large dose of virus are more likely to have severe disease and shed more virus.
  • Masking and social distancing decrease the viral dose.
• Children are unlikely to develop severe disease.
• Adults who have had COVID-19 or have been vaccinated are protected against severe disease.

Running several versions of these scenarios showed that the three mechanisms in combination set up a situation where an increasing proportion of the population will become predisposed for mild disease over the long term. The scientists felt the transformation was significant enough that it needed a new term. In this scenario, SARS-CoV-2 would become “Just Another Seasonal Coronavirus,” or JASC for short.

“In the beginning of the pandemic, no one had seen the virus before,” Adler explains. “Our immune system was not prepared.” The models show that as more adults become partially immune, whether through prior infection or vaccination, severe infections all but disappear over the next decade. Eventually, the only people who will be exposed to the virus for the first time will be children — and they’re naturally less prone to severe disease.

“The novel approach here is to recognize the competition taking place between mild and severe COVID-19 infections and ask which type will get to persist in the long run,” Beams says. “We’ve shown that mild infections will win, as long as they train our immune systems to fight against severe infections.”

The models do not account for every potential influence on disease trajectory. For example, if new virus variants overcome partial immunity, COVID-19 could take a turn for the worse. In addition, the predictions rely on the key assumptions of the model holding up.

“Our next step is comparing our model predictions with the most current disease data to assess which way the pandemic is going as it is happening,” Adler says. “Do things look like they’re heading in a bad or good direction? Is the proportion of mild cases increasing? Knowing that might affect decisions we make as a society.”

The research, published as “Will SARS-CoV-2 Become Just Another Seasonal Coronavirus?,” was supported by COVID MIND 2020 and the University of Utah.

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