The Daily Galaxy -Great Discoveries Channel, is an eclectic text and video presentation of news and original insights on science, space exploration and the environment and their reflections in popular culture (film, books, events). It provides news and original insights on science, space exploration, cosmology, astrobiology, and astrophysics.
The satellite communications that ships, planes and the military use to connect to the internet are vulnerable to hackers that, in the worst-case scenario, could carry out “cyber-physical attacks”, turning satellite antennas into weapons that operate, essentially, like microwave ovens.
According to research presented at the Black Hat information security conference in Las Vegas, continues Alex Hern in The Guardian, a number of popular satellite communication systems are vulnerable to the attacks, which could also leak information and hack connected devices. The attacks, which are merely a nuisance for the aviation sector, could pose a safety risk for military and maritime users, the research claims.
Ruben Santamarta (below), a researcher for the information security firm IOActive, carried out the study, building on research he presented in 2014. “The consequences of these vulnerabilities are shocking,” Santamarta said. “Essentially, the theoretical cases I developed four years ago are no longer theoretical.”
The attack works by connecting to the satellite antenna from the ground, through the internet, and then using security weaknesses in the software that operates the antenna to seize control.
From there, the potential damage varies. At the very least, the attack offers the ability to disrupt, intercept or modify all communications passed through the antenna, allowing an attacker to, for instance, eavesdrop on emails sent through an in-flight wifi system, or attempt to launch further hacking attacks against devices connected to the satellite network.
"The Cosmos must either be profoundly different than previously supposed or string theory must be wrong."
On June 25, Timm Wrase awoke in Vienna and groggily scrolled through an online repository of newly posted physics papers. One title startled him into full consciousness. The paper, by the prominent string theorist Cumrun Vafa of Harvard University and collaborators, conjectured a simple formula dictating which kinds of universes are allowed to exist and which are forbidden, according to string theory.
String theory, continues Natalie Wolchover in Quanta, permits a “landscape” of possible universes, surrounded by a “swampland” of logically inconsistent universes. In all of the simple, viable stringy universes physicists have studied, the density of dark energy is either diminishing or has a stable negative value, unlike our universe, which appears to have a stable positive value.
The leading candidate for a “theory of everything” weaving the force of gravity together with quantum physics, string theory defines all matter and forces as vibrations of tiny strands of energy. The theory permits some 10500 different solutions: a vast, varied “landscape” of possible universes. String theorists like Wrase and Vafa have strived for years to place our particular universe somewhere in this landscape of possibilities.
But now, Vafa and his colleagues were conjecturing that in the string landscape, universes like ours — or what ours is thought to be like — don’t exist. If the conjecture is correct, Wrase and other string theorists immediately realized, the cosmos must either be profoundly different than previously supposed or string theory must be wrong.
After dropping his kindergartner off that morning, Wrase went to work at the Vienna University of Technology, where his colleagues were also buzzing about the paper. That same day, in Okinawa, Japan, Vafa presented the conjecture at the Strings 2018 conference, which was streamed by physicists worldwide. Debate broke out on- and off-site. “There were people who immediately said, ‘This has to be wrong,’ other people who said, ‘Oh, I’ve been saying this for years,’ and everything in the middle,” Wrase said. There was confusion, he added, but “also, of course, huge excitement. Because if this conjecture was right, then it has a lot of tremendous implications for cosmology.”
In the image at the top of the page, the distribution of dark matter is shown in blue and the gas distribution in orange. This simulation is for the current state of the Universe and is centered on a massive galaxy cluster. The region shown is about 300 million light-years across. ESO/Illustris Collaboration
"The daysides of these worlds are furnaces that look more like a stellar atmosphere than a planetary atmosphere," said Vivien Parmentier, an astrophysicist at Aix Marseille University in France and lead author of the new study. "In this way, ultrahot Jupiters stretch out what we think planets should look like."
Imagine a place where the weather forecast is always the same: scorching temperatures, relentlessly sunny, and with absolutely zero chance of rain. This hellish scenario exists on the permanent daysides of a type of planet found outside our solar system dubbed an "ultrahot Jupiter." These worlds orbit extremely close to their stars, with one side of the planet permanently facing the star.
What has puzzled scientists is why water vapor appears to be missing from the toasty worlds' atmospheres, when it is abundant in similar but slightly cooler planets. Observations of ultrahot Jupiters by NASA's Spitzer and Hubble space telescopes, combined with computer simulations, have served as a springboard for a new theoretical study that may have solved this mystery.
According to the new study, ultrahot Jupiters do in fact possess the ingredients for water (hydrogen and oxygen atoms). But due to strong irradiation on the planet's daysides, temperatures there get so intense that water molecules are completely torn apart.
The simulated views of the ultrahot Jupiter WASP-121b below show what the planet might look like to the human eye from five different vantage points, illuminated to different degrees by its parent star. The images were created using a computer simulation being used to help scientists understand the atmospheres of these ultra-hot planets. NASA/JPL-Caltech/Vivien Parmentier/Aix-Marseille University (AMU)
While telescopes like Spitzer and Hubble can gather some information about the daysides of ultrahot Jupiters, the nightsides are difficult for current instruments to probe. The new paper proposes a model for what might be happening on both the illuminated and dark sides of these planets, based largely on observations and analysis of the ultrahot Jupiter known as WASP-121b, and from three recently published studies, coauthored by Parmentier, that focus on the ultrahot Jupiters WASP-103b, WASP-18b and HAT-P-7b, respectively.
The new study suggests that fierce winds may blow the sundered water molecules into the planets' nightside hemispheres. On the cooler, dark side of the planet, the atoms can recombine into molecules and condense into clouds, all before drifting back into the dayside to be splintered again.
Water is not the only molecule that may undergo a cycle of chemical reincarnation on these planets, according to the new study. Previous detections of clouds by Hubble at the boundary between day and night, where temperatures mercifully fall, have shown that titanium oxide (popular as a sunscreen) and aluminum oxide (the basis for ruby, the gemstone) could also be molecularly reborn on the ultrahot Jupiters' nightsides. These materials might even form clouds and rain down as liquid metals and fluidic rubies.
Among the growing catalog of planets outside our solar system -- known as exoplanets -- ultrahot Jupiters have stood out as a distinct class for about a decade. Found in orbits far closer to their host stars than Mercury is to our Sun, the giant planets are tidally locked, meaning the same hemisphere always faces the star, just as the Moon always presents the same side to Earth. As a result, ultrahot Jupiters' daysides broil in a perpetual high noon. Meanwhile, their opposite hemispheres are gripped by endless nights. Dayside temperatures reach between 3,600 and 5,400 degrees Fahrenheit (2,000 and 3,000 degrees Celsius), ranking ultrahot Jupiters among the hottest exoplanets on record. Nightside temperatures are around 1,800 degrees Fahrenheit cooler (1,000 degrees Celsius), cold enough for water to re-form and, along with other molecules, coalesce into clouds.
Hot Jupiters, cousins to ultrahot Jupiters with dayside temperatures below 3,600 degrees Fahrenheit (2,000 Celsius), were the first widely discovered type of exoplanet, starting back in the mid-1990s. Water has turned out to be common in their atmospheres. One hypothesis for why it appeared absent in ultrahot Jupiters has been that these planets must have formed with very high levels of carbon instead of oxygen. Yet the authors of the new study say this idea could not explain the traces of water also sometimes detected at the dayside-nightside boundary.
To break the logjam, Parmentier and colleagues took a cue from well-established physical models of the atmospheres of stars, as well as "failed stars," known as brown dwarfs, whose properties overlap somewhat with hot and ultrahot Jupiters. Parmentier adapted a brown dwarf model developed by Mark Marley, one of the paper's coauthors and a research scientist at NASA's Ames Research Center in Silicon Valley, California, to the case of ultrahot Jupiters. Treating the atmospheres of ultrahot Jupiters more like blazing stars than conventionally colder planets offered a way to make sense of the Spitzer and Hubble observations.
"With these studies, we are bringing some of the century-old knowledge gained from studying the astrophysics of stars, to the new field of investigating exoplanetary atmospheres," said Parmentier.
Spitzer's observations in infrared light zeroed in on carbon monoxide in the ultrahot Jupiters' atmospheres. The atoms in carbon monoxide form an extremely strong bond that can uniquely withstand the thermal and radiational assault on the daysides of these planets. The brightness of the hardy carbon monoxide revealed that the planets' atmospheres burn hotter higher up than deeper down. Parmentier said verifying this temperature difference was key for vetting Hubble's no-water result, because a uniform atmosphere can also mask the signatures of water molecules.
"These results are just the most recent example of Spitzer being used for exoplanet science -- something that was not part of its original science manifest," said Michael Werner, project scientist for Spitzer at NASA's Jet Propulsion Laboratory in Pasadena, California. "In addition, it's always heartening to see what we can discover when scientists combine the power of Hubble and Spitzer, two of NASA's Great Observatories."
Although the new model adequately described many ultrahot Jupiters on the books, some outliers do remain, suggesting that additional aspects of these worlds' atmospheres still need to be understood. Those exoplanets not fitting the mold could have exotic chemical compositions or unanticipated heat and circulation patterns. Prior studies have argued that there is a more significant amount of water in the dayside atmosphere of WASP-121b than what is apparent from observations, because most of the signal from the water is obscured. The new paper provides an alternative explanation for the smaller-than-expected water signal, but more studies will be required to better understand the nature of these ultrahot atmospheres.
Resolving this dilemma could be a task for NASA's next-generation James Webb Space Telescope, slated for a 2021 launch. Parmentier and colleagues expect it will be powerful enough to glean new details about the daysides, as well as confirm that the missing dayside water and other molecules of interest have gone to the planets' nightsides.
"We now know that ultrahot Jupiters exhibit chemical behavior that is different and more complex than their cooler cousins, the hot Jupiters," said Parmentier. "The studies of exoplanet atmospheres is still really in its infancy and we have so much to learn."
Artist view of Wasp 121b and its star shown at the top of the page: “Detecting the light emitted by hot steam in this exoplanet is a decisive step towards understanding how the atmospheres of such extreme planets work,” said David Ehrenreich, co-author of the study, associate professor at the University of Geneva and principal investigator of the European Research Council project FOUR ACES*. “Now the next step is to track down and identify the molecules responsible for the temperature rise”.
"There are no continents and mountains below Jupiter's atmosphere to obstruct the path of the jet streams," said Jeffrey Parker from Livermore National Laboratory.
Scientists from Australia and the United States have helped to solve the mystery underlying Jupiter's colored bands in a new study on the interaction between atmospheres and magnetic fields. Jupiter is the largest planet in our solar system. Unlike Earth, Jupiter has no solid surface - it is a gaseous planet, consisting mostly of hydrogen and helium.
Several strong jet streams flow west to east in Jupiter's atmosphere that are, in a way, similar to Earth's jet streams. Clouds of ammonia at Jupiter's outer atmosphere are carried along by these jet streams to form Jupiter's colored bands, which are shades white, red, orange, brown and yellow.
Dr Navid Constantinou from the ANU Research School of Earth Sciences, one of the researchers on the study, said that until recently little was known about what happened below Jupiter's clouds. "We know a lot about the jet streams in Earth's atmosphere and the key role they play in the weather and climate, but we still have a lot to learn about Jupiter's atmosphere," he said.
"Scientists have long debated how deep the jet streams reach beneath the surfaces of Jupiter and other gas giants, and why they do not appear in the sun's interior."
Recent evidence from NASA's spacecraft Juno indicates these jet streams reach as deep as 3,000 kilometeres below Jupiter's clouds. Co-researcher Parker said their theory showed that jet streams were suppressed by a strong magnetic field.
The image at the top of the page captures a high-altitude cloud formation surrounded by swirling patterns in the atmosphere of Jupiter's North North Temperate Belt region.
"The gas in the interior of Jupiter is magnetized, so we think our new theory explains why the jet streams go as deep as they do under the gas giant's surface but don't go any deeper," said Parker.
The polar and subtropical jet streams in Earth's atmosphere shape the climate, especially in the mid-latitudes such as in Australia, Europe and North America. "Earth's jet streams have a huge impact on the weather and climate by acting as a barrier and making it harder for air on either side of them to exchange properties such as heat, moisture and carbon," said Constantinou.
The jet streams on Earth are wavy and irregular, while they are much straighter on Jupiter. "This makes the jet streams on Jupiter simpler. By studying Jupiter, not only do we unravel the mysteries in the interior of the gas giant, but we can also use Jupiter as a laboratory for studying how atmospheric flows work in general."
The research involved mathematical calculations for the instability that leads to jet streams when magnetic fields are present, as well as work comparing the theoretical predictions with results from previous computer simulations.
The Daily Galaxy via Australian National University
Just as cars need fossil fuels to power their engines, the living cells that make up our bodies use food as a fuel source. To harness the energy in food every cell in our bodies contains microscopic biological machines, known as mitochondria, which convert food molecules into energy.
Researchers at The University of Western Australia and Harry Perkins Institute of Medical Research have made a fundamental discovery about of the atomic structure and function of the biological 'factories' in cells that make energy, providing a new means to target the 'machines' within factories for drug treatments.
How Mitochondria Produce Energy - YouTube
The research, published today in Nature, was led by Professor Nenad Ban from ETH Zurich in Switzerland, in collaboration with researchers from UWA's School of Molecular Sciences and Harry Perkins Institute of Medical Research: Associate Professor Aleksandra Filipovska, Head of Mitochondrial Medicine and Biology, Associate Professor Oliver Rackham, Head of Synthetic Biology and Drug Discovery and their Ph.D. student Richard Lee.
Professor Filipovska said mitochondria were microscopic, energy-producing factories found in all eukaryotic cells, or cells containing a nucleus enclosed within membranes, representing all forms of life that are visible without a microscope.
"Mitochondria contain a set of genes that are used to make key protein building blocks that enable mitochondria to produce energy," she said. "These proteins are essential for energy production however little is known about how they are made. The recent discovery of the atomic structure of the machine that makes these proteins (the mitochondrial ribosome) has revealed how they are made.
"Surprisingly, this machine blocks itself from making the proteins until it is precisely located where these proteins are required within mitochondria. This is highly unusual and previously not found in nature."
Professor Filipovska said as well as providing a new means to target this molecular machine for drug treatments, the discovery also demonstrated the power of cutting-edge technology to reveal how living systems had evolved to function under different energy requirements.
"Defects in mitochondrial function underlie many common diseases such as neurodegenerative, metabolic and heart diseases, cancer, diabetes and ageing," she said. "Therefore molecular discoveries provide the much-needed knowledge that enables us to make the leap to disease treatments and drug discoveries."
The next step was to delve deeper into the role of the mitochondrial ribosome to understand how its defects could cause disease, Professor Filipovska said.
"We are now working on developing models of disease to study these defects. We are using our models to screen for drugs that can selectively rescue defects in protein synthesis and energy production."
The Daily Galaxy via University of Western Australia
"A megalodon mouth is so big that you could swim into it without touching any of the teeth. It literally could swallow a small car without having to chomp down on it. And the teeth would be about 7 inches or 17 centimeters tall, and it would have several rows in its mouth at once, so as it lost or broke teeth, it could easily replace them."
In the new action movie The Meg, Jason Statham battles an 18-meter-long megalodon, a beast of a shark that lived 20 million years ago. The film posits that a few members of the species are still alive, free to terrorize cargo ships, beachgoers, and even tiny dogs off the coast of China.
The Meg International Trailer (2018) - YouTube
If you’re not expecting a lot of scientific accuracy from a movie like this, you won’t be disappointed. But, after a screening, Frankie Schembri at Science sat down with Hans Sues, curator of vertebrate paleobiology at the Smithsonian Institution’s National Museum of Natural History in Washington, D.C., and an expert on all creatures prehistoric, to see whether the film got anything right.
Sues has assisted in the discovery of several new species of dinosaurs and even has one named after him—the dome-skulled pachycephalosaur Hanssuesia sternbergi. He’s now supervising the building of a 15-meter megalodon model for a new space in the museum, which is undergoing renovations.
So violent was the eruption, some have speculated, that it ended the once-prosperous Minoan civilization, instigated a volcanic winter as far away as China, and inspired the 12 plagues of Exodus as well as the myth of Atlantis—claims that are to varying degrees controversial. But nothing is as controversial, it turns out, as the debate over when the Santorini volcano actually erupted.
The latest controversy in a bitter archaeological dispute involves a literal olive branch, continues Sarah Zhang in The Atlantic. The olive branch comes from the Greek island of Santorini, where a volcano erupted over three millennia ago, spewing gas, ash, pumice, and boulders into the sky. Once depleted, the volcano collapsed in on itself.
Santorini Volcano History - Vimeo
The olive branch was supposed to help resolve this. In the 2000s, the geoscientist Walter Friedrich and his graduate student Tom Pfeiffer at the University of Aarhaus found the branch in Santorini under several feet of pumice from that ancient eruption. It looked as if it had been buried alive. They got excited. Because trees grow a new ring every year, the variation in carbon-14 from year to year can be “wiggle-matched” to historical levels of carbon-14 in the atmosphere. Using this method, Friedrich arrived at an eruption date of 1627 to 1600 BC—a full century earlier than what archaeologists had previously decided based on pottery found near Santorini and elsewhere. The archeologists were not pleased.
It does not help that olive wood is notoriously hard to date. Olive wood doesn’t have clearly delineated rings. Its branches don’t grow in perfect concentric circles. Instead, a new paper in Scientific Reports finds, parts of a branch can stop growing for years and even decades before a tree dies. The olive branch in Santorini, depending on what part of it is sampled, may not give an accurate date for the volcano’s eruption. “It’s a beautiful tree full of significance for us,” Elisabetta Boaretto, a radiocarbon-dating researcher at the Weizmann Institute of Science who led the study, says of the olive tree. “But it’s a difficult tree. It likes to keep its secrets.”
Sturt Manning, an archaeologist and tree-ring researcher at Cornell—who, for the record, also believes the radiocarbon dating suggests an eruption date of around 1600 BC—points out that accounting for this problem would only move the date a few decades. That still doesn’t get to 1500 BC, the date many old-school archaeologists continue to defend. But he predicts the uncertainty raised in this paper will have consequences. “[Critics] will cite this paper for the next 50 years as one of the reasons to always be a bit worried about what scientists say,” says Manning.
"I wonder if giving up gods and aliens will lead people to the weird singularity of the human mind. Our species hosts what is probably the only example of technological intelligence. The human brain will most likely remain the most complex organization of matter in the universe. And all of us manifest this intelligence—this entity alien to the rest of space and time. The weird thing, the mysterious and story-provoking thing, isn’t that we have too little meaning. It’s that we have too much of it. It seems out of place in a silent galaxy. That’s the idea we’ll have to get used to. Newly rich with galactic meaning, humankind is finally free to see its loneliness as awe-inspiring rather than tragic."
Ever since the Renaissance, continues Michael W, Clune in The Atlantic, the sciences have dealt human beings a steady stream of humiliations. The Copernican revolution dismantled the idea that humanity stood at the center of the universe. A cascade of discoveries from the late-18th to the early-20th century showed that humanity was a lot less significant than some had imagined. The revelation of the geological timescale stacked millions and billions of years atop our little cultural narratives, crumbling all of human history to dust. The revelation that we enjoy an evolutionary kinship to fish, bugs, and filth eroded the in-God’s-image stuff. The disclosure of the size of the galaxy—and our position on a randomly located infinitesimal dot in it—was another hit to human specialness. Then came relativity and quantum mechanics, and the realization that the way we see and hear the world bears no relation to the bizarre swarming of its intrinsic nature.
Literature began to taste and probe these discoveries. By the 19th century, some writers had already hit upon the theme—meaninglessness—that would come to dominate the 20th century in a thousand scintillating variations, from H. P. Lovecraft’s Cthulhu stories to Samuel Beckett’s plays. But by the turn of the new millennium, it had become clear that this sense of meaninglessness was no longer up to date.
In 1961, Frank Drake developed an equation with a string of variables to try to determine the frequency of intelligent life. Over the years, some of the variables have been plugged in. Maybe planets are just very rare? They’re not. Perhaps few planets orbit their star in the “Goldilocks zone” where it isn’t too hot or cold? No, it seems that lots do. This may sound like another round of Copernican humiliation: In a galaxy with up to 400 billion stars, many with orbiting planets, surely there’s some other intelligent, technological species. But humans have been scanning the spectra for decades and have found nothing.
Earlier this year, a group at the University of Oxford released a paper arguing that our knowledge of the universe and of math should lead us to assume that intelligent life is most probably an extremely rare event, depending on a series of fortuitous circumstances—like the weirdly large size of our moon, perhaps— that are so unlikely as to almost never happen. Humanity shouldn’t be surprised that we haven’t found aliens, because most likely there aren’t any.
It’s important to note that these arguments depend on probabilities, and that our search for intelligent life in the cosmos is still woefully incomplete. But even so, it looks increasingly possible that humans may indeed be alone, or that we might have some mind-bogglingly gigantic region of the cosmos to ourselves. As this idea slowly seeps into our consciousness, it’s going to have deep cultural consequences. The mental habits of two centuries will lead us to strenuously resist this new picture of the galaxy, especially since, from ancient myths to postmodern sci-fi, humanity has almost always understood itself in relation to a nonhuman or superhuman Other.
If the revelation that humans are probably alone in our universe stands, and as that revelation sinks into our collective psyche, it could effect a second, weirder Copernican revolution in culture. To begin with, it’s really hard to square humanity’s status as perhaps the only intelligent species in all of time and space with the idea that we are insignificant. To the contrary, the everyday breath of the least of us contains meaning in so concentrated a form that a cup’s worth of it could be doled out to a dozen star systems, transforming the arid matter into a garden of significance.
"A rare 'survivor' that somehow clung on through the Cambrian explosion: so-called Ediacaran organisms have puzzled biologists for decades. To the untrained eye they look like fossilized plants, in tube or frond shapes up to 2 meters long. These strange life forms dominated Earth’s seas half a billion years ago, and scientists have long struggled to figure out whether they’re algae, fungi, or even an entirely different kingdom of life that failed to survive. Now, two paleontologists think they have finally established the identity of the mysterious creatures: They were animals, some of which could move around, but they were unlike any living on Earth today."
The Ediacaran organisms, continues Colin Barras in Science, represent the first major explosion of complex life on Earth, and they thrived for 30 million years. Their demise has been linked to the appearance of animals in the Cambrian Explosion, Hoyal Cuthill says. But that simple explanation doesn’t work as well if Ediacaran organisms were animals themselves, and some were still alive tens of millions of years later. “It’s not quite so neat anymore,” she says. “As to what led to their eventual extinction I think it’s very hard to say.”
Scientists first discovered the Ediacaran organisms in 1946 in South Australia’s Ediacara Hills. To date, researchers have identified about 200 different types in ancient rocks across the world. Almost all appear to have died out by 541 million years ago, just before fossils of familiar animals like sponges and the ancestors of crabs and lobsters appeared in an event dubbed the Cambrian explosion. One reason these creatures have proved so tricky to place in the tree of life is that some of them had an anatomy unique in nature. Their bodies were made up of branched fronds with a strange fractal architecture, in which the frond subunits resembled small versions of the whole frond.
Jennifer Hoyal Cuthill at the Tokyo Institute of Technology and the University of Cambridge in the United Kingdom and Jian Han at Northwest University in Xi’an, China, have now found key evidence that the Ediacaran organisms were animals. They analyzed more than 200 fossils of a 518-million-year-old marine species named Stromatoveris psygmoglena. Paleontologists had previously concluded that the 10-centimeter-tall species was some sort of animal—in part, says Hoyal Cuthill, because it was found alongside other known animals, and all of the fossils are preserved in a similar way. Hoyal Cuthill and Han argue S. psygmoglena was also an Ediacaran organism.
"By the time she is about three years old, a child has usually endured her first influenza infection. If it’s a nasty bout, her temperature will rise and her muscles will ache. She’s probably young enough that she won’t recall the illness — but her immune system will."
When the virus enters her body, continues Declan Butler in Nature, its presence prompts a pool of immature, unprogrammed immune cells to start competing to become the flu’s tracker and assassin. The winners — cells that bind most strongly to the virus — store a memory of the pathogen, ready to recognize and attack it the next time it strikes.
An image of the devastating 1918 ‘Spanish Flu’ pandemic.
But influenza is an inveterate shape-shifter. Regions of its outer proteins can mutate as it replicates, allowing it to avoid immune detection. When infections with new flu strains occur later in life, the immune system will mount a response based on that first encounter, reacting strongly to recognized regions of the virus, but not to any that have changed. Immune cells can’t tailor any novel antibodies that could help.
How exactly the immune system ‘imprints’ on its first-encountered strains presents a tantalizing puzzle to flu researchers — and solving it could help to combat the virus and improve vaccines.
Scientists suspect that understanding how imprinting works could help them to predict who will suffer most from seasonal strains and pandemics. Mounting evidence suggests that some people fare worse in deadly flu pandemics because their first childhood exposure was to a different version of the virus. Researchers think that this is why young adults experienced higher mortality than other age groups during the deadly 1918 pandemic, in which an estimated 50 million people died worldwide.
Knowledge of imprinting could help virologists to develop more-effective seasonal vaccines that could counteract circulating strains for several years, and a long-sought universal flu vaccine that could protect people for life against entirely new — and potentially pandemic-provoking — subtypes of flu. Imprinting seems to offer some immunity to flu strains related to the first infection. This broad immunity is often seen as a sign that the immune system could be coaxed into offering wide protection. “It does give us hope that we may be able to elicit a broadly protective immune response,” says Aubree Gordon, an epidemiologist at the University of Michigan in Ann Arbor.
Existing flu vaccines could certainly do with some help. Their effects wear off after a few months, and they aren’t very effective even in that brief window; during the 2017–18 flu season in the United States, people who received the vaccine were only 36% less likely to contract flu than those who weren’t immunized, although vaccination can lessen the severity of symptoms in those who do become ill.
Imprinting might help to explain these shortfalls. But right now, the mechanisms behind this process are poorly understood, says Jennifer Nayak, a paediatric immunologist at the University of Rochester Medical Center in New York. Getting to grips with imprinting will be important to researchers who hope to tailor a universal vaccine to fit people with different past flu exposures, says Scott Hensley, a viral immunologist at the University of Pennsylvania in Philadelphia. “The same vaccine given to different people will likely elicit different immune responses, depending on their history,” he says.
In April, the US National Institute of Allergy and Infectious Diseases (NIAID) in Bethesda, Maryland, called for researchers to pitch projects that would explore the effects of imprinting on immunity, as part of a wider effort to fund research into a universal flu vaccine. The agency plans to spend US$5 million on a large cohort study that will recruit and monitor infants from birth for at least three flu seasons to explore at the molecular level how their immune systems respond to initial exposure and subsequent flu infections and vaccinations. Immunizations are usually recommended for babies over 6 months of age.