“Coming Back from the Dead” Is No Longer Science Fiction
Last year, there were widespread reports of a 53-year-old Frenchman who had suffered a cardiac arrest and "died," but was then resuscitated back to life 18 hours after his heart had stopped.
The once black-and-white line between life and death is now blurrier than ever.
This was thought to have been possible in part because his body had progressively cooled down naturally after his heart had stopped, through exposure to the outside cold. The medical team who revived him were reported as being "stupefied" that they had been able to bring him back to life, in particular since he had not even suffered brain damage.
Interestingly, this man represents one of a growing number of extraordinary cases in which people who would otherwise be declared dead have now been revived. It is a testament to the incredible impact of resuscitation science -- a science that is providing opportunities to literally reverse death, and in doing so, shedding light on the age-old question of what happens when we die.
Death: Past and Present
Throughout history, the boundary between life and death was marked by the moment a person's heart stopped, breathing ceased, and brain function shut down. A person became motionless, lifeless, and was deemed irreversibly dead. This is because once the heart stops beating, blood flow stops and oxygen is cut off from all the body's organs, including the brain. Consequently, within seconds, breathing stops and brain activity comes to a halt. Since the cessation of the heart literally occurs in a "moment," the philosophical notion of a specific point in time of "irreversible" death still pervades society today. The law, for example, relies on "time of death," which corresponds to when the heart stops beating.
The advent of cardiopulmonary resuscitation (CPR) in the 1960s was revolutionary, demonstrating that the heart could potentially be restarted after it had stopped, and what had been a clear black-and-white line was shown to be potentially reversible in some people. What was once called death—the ultimate end point— was now widely called cardiac arrest, and became a starting point.
From then on, it was only if somebody had requested not to be resuscitated or when CPR was deemed to have failed that people would be declared dead by "cardiopulmonary criteria." Biologically, cardiac arrest and death by cardiopulmonary criteria are the same process, albeit marked at different points in time depending on when a declaration of death is made.
The apparent irreversibility of death as we know it may not necessarily reflect true irretrievable cellular damage inside the body.
Clearly, contrary to many people's perceptions, cardiac arrest is not a heart attack; it is the final step in death irrespective of cause, whether it be a stroke, a heart attack, a car accident, an overwhelming infection or cancer. This is how roughly 95 percent of the population are declared dead.
The only exception is the small proportion of people who may have suffered catastrophic brain injuries, but whose hearts can be artificially kept beating for a period of time on life-support machines. These people can be legally declared dead based on brain death criteria before their hearts have stopped. This is because the brain can die either from oxygen starvation after cardiac arrest or from massive trauma and internal bleeding. Either way, the brain dies hours or possibly longer after these injuries have taken place and not just minutes.
A Profound Realization
What has become increasingly clear is that the apparent irreversibility of death as we know it may not necessarily reflect true irretrievable cellular damage inside the body. This is consistent with a mounting understanding: it is only after a person actually dies that the cells in the body start to undergo their own process of death. Intriguingly, this process is something that can now be manipulated through medical intervention. Being cold is one of the factors that slows down the rate of cellular decay. The 53-year-old Frenchman's case and the other recent cases of resuscitation after prolonged periods of time illustrate this new understanding.
Last week's earth-shattering announcement by neuroscientist Dr. Nenad Sestan and his team out of Yale, published in the prestigious scientific journal Nature, provides further evidence that a time gap exists between actual death and cellular death in cadavers. In this seminal study, these researchers were able to restore partial function in pig brains four hours after their heads were severed from their bodies. These results follow from the pioneering work in 2001 of geneticist Fred Gage and colleagues from the Salk Institute, also published in Nature, which demonstrated the possibility of growing human brain cells in the laboratory by taking brain biopsies from cadavers in the mortuary up to 21 hours post-mortem.
The once black-and-white line between life and death is now blurrier than ever. Some people may argue this means these humans and pigs weren't truly "dead." However, that is like saying the people who were guillotined during the French Revolution were also not dead. Clearly, that is not the case. They were all dead. The problem is not death; it's our reliance on an outdated philosophical, rather than biological, notion of death.
Death can no longer be considered an absolute moment but rather a process that can be reversed even many hours after it has taken place.
But the distinction between irreversibility from a medical perspective and biological irreversibility may not matter much from a pragmatic perspective today. If medical interventions do not exist at any given time or place, then of course death cannot be reversed.
However, it is crucial to distinguish between biologically and medically: When "irreversible" loss of function arises due to inadequate treatment, then a person could be potentially brought back in the future when an alternative therapy becomes available, or even today if he or she dies in a location where novel treatments can slow down the rate of cell death. However, when true irreversible loss of function arises from a biological perspective, then no treatment will ever be able to reverse the process, whether today, tomorrow, or in a hundred years.
Probing the "Grey Zone"
Today, thanks to modern resuscitation science, death can no longer be considered an absolute moment but rather a process that can be reversed even many hours after it has taken place. How many hours? We don't really know.
One of the wider implications of our medical advances is that we can now study what happens to the human mind and consciousness after people enter the "grey zone," which marks the time after the heart stops, but before irreversible and irretrievable cell damage occurs, and people are then brought back to life. Millions have been successfully revived and many have reported experiencing a unique, universal, and transformative mental state.
Were they "dead"? Yes, according to all the criteria we have ever used. But they were able to be brought back before their "dead" bodies had reached the point of permanent, irreversible cellular damage. This reflects the period of death for all of us. So rather than a "near-death experience," I prefer a new terminology to describe these cases -- "an actual-death experience." These survivors' unique experiences are providing eyewitness testimonies of what we will all be likely to experience when we die.
Such an experience reportedly includes seeing a warm light, the presence of a compassionate perfect individual, deceased relatives, a review of their lives, a judgment of their actions and intentions as they pertain to their humanity, and in some cases a sensation of seeing doctors and nurses working to resuscitate them.
Are these experiences compatible with hallucinations or illusions? No -- in part, because these people have described real, verifiable events, which, by definition are not hallucinations, and in part, because their experiences are not compatible with confused and delirious memories that characterize oxygen deprivation.
The challenge for us scientifically is understanding how this is possible at a time when all our science tells us the brain shuts down.
For instance, it is hard to classify a structured meaningful review of one's life and one's humanity as hallucinatory or illusory. Instead, these experiences represent a new understanding of the overall human experience of death. As an intensive care unit physician for more than 10 years, I have seen numerous cases where these reports have been corroborated by my colleagues. In short, these survivors have been known to come back with reports of full consciousness, with lucid, well-structured thought processes and memory formation.
The challenge for us scientifically is understanding how this is possible at a time when all our science tells us the brain shuts down. The fact that these experiences occur is a paradox and suggests the undiscovered entity we call the "self," "consciousness," or "psyche" – the thing that makes us who we are - may not become annihilated at the point of so-called death.
At New York University, the State University of New York, and across 20 hospitals in the U.S. and Europe, we have brought together a new multi-disciplinary team of experts across many specialties, including neurology, cardiology, and intensive care. Together, we hope to improve cardiac arrest prevention and treatment, as well as to address the impact of new scientific discoveries on our understanding of what happens at death.
One of our first studies, Awareness during Resuscitation (AWARE), published in the medical journal Resuscitation in 2014, confirmed that some cardiac arrest patients report a perception of awareness without recall; others report detailed memories and experiences; and a few report full auditory and visual awareness and consciousness of their experience, from a time when brain function would be expected to have ceased.
While you probably have some opinion or belief about this based upon your own philosophical, religious, or cultural background, you may not realize that exploring what happens when we die is now a subject that science is beginning to investigate.
There is no question more intriguing to humankind. And for the first time in our history, we may finally uncover some real answers.
The Inside Story of Two Young Scientists Who Helped Make Moderna's Covid Vaccine Possible
In early 2020, Moderna Inc. was a barely-known biotechnology company with an unproven approach. It wanted to produce messenger RNA molecules to carry instructions into the body, teaching it to ward off disease. Experts doubted the Boston-based company would meet success.
Today, Moderna is a pharmaceutical power thanks to its success developing an effective Covid-19 vaccine. The company is worth $124 billion, more than giants including GlaxoSmithKline and Sanofi, and evidence has emerged that Moderna's shots are more protective than those produced by Pfizer-BioNTech and other vaccine makers. Pressure is building on the company to deliver more of its doses to people around the world, especially in poorer countries, and Moderna is working on vaccines against other pathogens, including Zika, influenza and cytomegalovirus.
But Moderna encountered such difficulties over the course of its eleven-year history that some executives worried it wouldn't survive. Two unlikely scientists helped save the company. Their breakthroughs paved the way for Moderna's Covid-19 shots but their work has never been publicized nor have their contributions been properly appreciated.
Derrick Rossi, a scientist at MIT, and Noubar Afeyan, a Cambridge-based investor, launched Moderna in September 2010. Their idea was to create mRNA molecules capable of delivering instructions to the body's cells, directing them to make proteins to heal ailments and cure disease. Need a statin, immunosuppressive, or other drug or vaccine? Just use mRNA to send a message to the body's cells to produce it. Rossi and Afeyan were convinced injecting mRNA into the body could turn it into its own laboratory, generating specific medications or vaccines as needed.
At the time, the notion that one might be able to teach the body to make proteins bordered on heresy. Everyone knew mRNA was unstable and set off the body's immune system on its way into cells. But in the late 2000's, two scientists at the University of Pennsylvania, Katalin Karikó and Drew Weissman, had figured out how to modify mRNA's chemical building blocks so the molecule could escape the notice of the immune system and enter the cell. Rossi and Afeyan couldn't convince the University of Pennsylvania to license Karikó and Weissman's patent, however, stymying Moderna's early ambitions. At the same time, the Penn scientists' technique seemed more applicable to an academic lab than a biotech company that needed to produce drugs or shots consistently and in bulk. Rossi and Afeyan's new company needed their own solution to help mRNA evade the body's defenses.
Some of Moderna's founders doubted Schrum could find success and they worried if their venture was doomed from the start.
The Scientist Who Modified mRNA: Jason Schrum
In 2010, Afeyan's firm subleased laboratory space in the basement of another Cambridge biotech company to begin scientific work. Afeyan chose a young scientist on his staff, Jason Schrum, to be Moderna's first employee, charging him with getting mRNA into cells without relying on Karikó and Weissman's solutions.
Schrum seemed well suited for the task. Months earlier, he had received a PhD in biological chemistry at Harvard University, where he had focused on nucleotide chemistry. Schrum even had the look of someone who might do big things. The baby-faced twenty-eight-year-old favored a relaxed, start-up look: khakis, button-downs, and Converse All-Stars.
Schrum felt immediate strain, however. He hadn't told anyone, but he was dealing with intense pain in his hands and joints, a condition that later would be diagnosed as degenerative arthritis. Soon Schrum couldn't bend two fingers on his left hand, making lab work difficult. He joined a drug trial, but the medicine proved useless. Schrum tried corticosteroid injections and anti-inflammatory drugs, but his left hand ached, restricting his experiments.
"It just wasn't useful," Schrum says, referring to his tender hand.*
He persisted, nonetheless. Each day in the fall of 2010, Schrum walked through double air-locked doors into a sterile "clean room" before entering a basement laboratory, in the bowels of an office in Cambridge's Kendall Square neighborhood, where he worked deep into the night. Schrum searched for potential modifications of mRNA nucleosides, hoping they might enable the molecule to produce proteins. Like all such rooms, there were no windows, so Schrum had to check a clock to know if it was day or night. A colleague came to visit once in a while, but most of the time, Schrum was alone.
Some of Moderna's founders doubted Schrum could find success and they worried if their venture was doomed from the start. An established MIT scientist turned down a job with the start-up to join pharmaceutical giant Novartis, dubious of Moderna's approach. Colleagues wondered if mRNA could produce proteins, at least on a consistent basis.
As Schrum began testing the modifications in January 2011, he made an unexpected discovery. Karikó and Weissman saw that by turned one of the building blocks for mRNA, a ribonucleoside called uridine, into a slightly different form called pseudouridine, the cell's immune system ignored the mRNA and the molecule avoided an immune response. After a series of experiments in the basement lab, Schrum discovered that a variant of pseudouridine called N1- methyl-pseudouridine did an even better job reducing the cell's innate immune response. Schrum's nucleoside switch enabled even higher protein production than Karikó and Weissman had generated, and Schrum's mRNAs lasted longer than either unmodified molecules or the modified mRNA the Penn academics had used, startling the young researcher. Working alone in a dreary basement and through intense pain, he had actually improved on the Penn professors' work.
Years later, Karikó and Weissman who would win acclaim. In September 2021, the scientists were awarded the Lasker-DeBakey Clinical Medical Research Award. Some predict they eventually will win a Nobel prize. But it would be Schrum's innovation that would form the backbone of both Moderna and Pfizer-BioNTech's Covid-19 vaccine, not the chemical modifications that Karikó and Weissman developed. For Schrum, necessity had truly been the mother of invention.
The Scientist Who Solved Delivery: Kerry Benenato
For several years, Moderna would make slow progress developing drugs to treat various diseases. Eventually, the company decided that mRNA was likely better suited for vaccines. By 2017, Moderna and the National Institutes of Health were discussing working together to develop mRNA–based vaccines, a partnership that buoyed Moderna's executives. There remained a huge obstacle in Moderna's way, however. It was up to Kerry Benenato to find a solution.
Benenato received an early hint of the hurdle in front of her three years earlier, when the organic chemist was first hired. When a colleague gave her a company tour, she was introduced to Moderna's chief scientific officer, Joseph Bolen, who seemed unusually excited to meet her.
"Oh, great!" Bolen said with a smile. "She's the one who's gonna solve delivery."
Bolen gave a hearty laugh and walked away, but Benenato detected seriousness in his quip.
Solve delivery?
It was a lot to expect from a 37-year-old scientist already dealing with insecurities and self-doubt. Benenato was an accomplished researcher who most recently had worked at AstraZeneca after completing post-doctoral studies at Harvard University. Despite her impressive credentials, Benenato battled a lack of confidence that sometimes got in her way. Performance reviews from past employers had been positive, but they usually produced similar critiques: Be more vocal. Do a better job advocating for your ideas. Give us more, Kerry.
Benenato was petite and soft-spoken. She sometimes stuttered or relied on "ums" and "ahs" when she became nervous, especially in front of groups, part of why she sometimes didn't feel comfortable speaking up.
"I'm an introvert," she says. "Self-confidence is something that's always been an issue."
To Benenato, Moderna's vaccine approach seemed promising—the team was packaging mRNAs in microscopic fatty-acid compounds called lipid nanoparticles, or LNPs, that protected the molecules on their way into cells. Moderna's shots should have been producing ample and long-lasting proteins. But the company's scientists were alarmed—they were injecting shots deep into the muscle of mice, but their immune systems were mounting spirited responses to the foreign components of the LNPs, which had been developed by a Canadian company.
This toxicity was a huge issue: A vaccine or drug that caused sharp pain and awful fevers wasn't going to prove very popular. The Moderna team was in a bind: Its mRNA had to be wrapped in the fatty nanoparticles to have a chance at producing plentiful proteins, but the body wasn't tolerating the microscopic encasements, especially upon repeated dosing.
The company's scientists had done everything they could to try to make the molecule's swathing material disappear soon after entering the cells, in order to avoid the unfortunate side effects, such as chills and headaches, but they weren't making headway. Frustration mounted. Somehow, the researchers had to find a way to get the encasements—made of little balls of fat, cholesterol, and other substances—to deliver their payload mRNA and then quickly vanish, like a parent dropping a teenager off at a party, to avoid setting off the immune system in unpleasant ways, even as the RNA and the proteins the molecule created stuck around.
Benenato wasn't entirely shocked by the challenges Moderna was facing. One of the reasons she had joined the upstart company was to help develop its delivery technology. She just didn't realize how pressing the issue was, or how stymied the researchers had become. Benenato also didn't know that Moderna board members were among those most discouraged by the delivery issue. In meetings, some of them pointed out that pharmaceutical giants like Roche Holding and Novartis had worked on similar issues and hadn't managed to develop lipid nanoparticles that were both effective and well tolerated by the body. Why would Moderna have any more luck?
Stephen Hoge insisted the company could yet find a solution.
"There's no way the only innovations in LNP are going to come from some academics and a small Canadian company," insisted Hoge, who had convinced the executives that hiring Benenato might help deliver an answer.
Benenato realized that while Moderna might have been a hot Boston-area start- up, it wasn't set up to do the chemistry necessary to solve their LNP problem. Much of its equipment was old or secondhand, and it was the kind used to tinker with mRNAs, not lipids.
"It was scary," she says.
When Benenato saw the company had a nuclear magnetic resonance spectrometer, which allows chemists to see the molecular structure of material, she let out a sigh of relief. Then Benenato inspected the machine and realized it was a jalopy. The hulking, aging instrument had been decommissioned and left behind by a previous tenant, too old and banged up to bring with them.
Benenato began experimenting with different chemical changes for Moderna's LNPs, but without a working spectrometer she and her colleagues had to have samples ready by noon each day, so they could be picked up by an outside company that would perform the necessary analysis. After a few weeks, her superiors received an enormous bill for the outsourced work and decided to pay to get the old spectrometer running again.
After months of futility, Benenato became impatient. An overachiever who could be hard on herself, she was eager to impress her new bosses. Benenato felt pressure outside the office, as well. She was married with a preschool-age daughter and an eighteen-month-old son. In her last job, Benenato's commute had been a twenty-minute trip to Astra-Zeneca's office in Waltham, outside Boston; now she was traveling an hour to Moderna's Cambridge offices. She became anxious—how was she going to devote the long hours she realized were necessary to solve their LNP quandary while providing her children proper care? Joining Moderna was beginning to feel like a possible mistake.
She turned to her husband and father for help. They reminded her of the hard work she had devoted to establishing her career and said it would be a shame if she couldn't take on the new challenge. Benenato's husband said he was happy to stay home with the kids, alleviating some of her concerns.
Back in the office, she got to work. She wanted to make lipids that were easier for the body to chop into smaller pieces, so they could be eliminated by the body's enzymes. Until then, Moderna, like most others, relied on all kinds of complicated chemicals to hold its LNP packaging together. They weren't natural, though, so the body was having a hard time breaking them down, causing the toxicity.
Benenato began experimenting with simpler chemicals. She inserted "ester bonds"—compounds referred to in chemical circles as "handles" because the body easily grabs them and breaks them apart. Ester bonds had two things going for them: They were strong enough to help ensure the LNP remained stable, acting much like a drop of oil in water, but they also gave the body's enzymes something to target and break down as soon as the LNP entered the cell, a way to quickly rid the body of the potentially toxic LNP components. Benenato thought the inclusion of these chemicals might speed the elimination of the LNP delivery material.
This idea, Benenato realized, was nothing more than traditional, medicinal chemistry. Most people didn't use ester bonds because they were pretty unsophisticated. But, hey, the tricky stuff wasn't working, so Benenato thought she'd see if the simple stuff worked.
Benenato also wanted to try to replace a group of unnatural chemicals in the LNP that was contributing to the spirited and unwelcome response from the immune system. Benenato set out to build a new and improved chemical combination. She began with ethanolamine, a colorless, natural chemical, an obvious start for any chemist hoping to build a more complex chemical combination. No one relied on ethanolamine on its own.
Benenato was curious, though. What would happen if she used just these two simple modifications to the LNP: ethanolamine with the ester bonds? Right away, Benenato noticed her new, super-simple compound helped mRNA create some protein in animals. It wasn't much, but it was a surprising and positive sign. Benenato spent over a year refining her solution, testing more than one hundred variations, all using ethanolamine and ester bonds, showing improvements with each new version of LNP. After finishing her 102nd version of the lipid molecule, which she named SM102, Benenato was confident enough in her work to show it to Hoge and others.
They immediately got excited. The team kept tweaking the composition of the lipid encasement. In 2017, they wrapped it around mRNA molecules and injected the new combination in mice and then monkeys. They saw plentiful, potent proteins were being produced and the lipids were quickly being eliminated, just as Benenato and her colleagues had hoped. Moderna had its special sauce.
That year, Benenato was asked to deliver a presentation to Stephane Bancel, Moderna's chief executive, Afeyan, and Moderna's executive committee to explain why it made sense to use the new, simpler LNP formulation for all its mRNA vaccines. She still needed approval from the executives to make the change. Ahead of the meeting, she was apprehensive, as some of her earlier anxieties returned. But an unusual calm came over her as she began speaking to the group. Benenato explained how experimenting with basic, overlooked chemicals had led to her discovery.
She said she had merely stumbled onto the company's solution, though her bosses understood the efforts that had been necessary for the breakthrough. The board complimented her work and agreed with the idea of switching to the new LNP. Benenato beamed with pride.
"As a scientist, serendipity has been my best friend," she told the executives.
Over the next few years, Benenato and her colleagues would improve on their methods and develop even more tolerable and potent LNP encasement for mRNA molecules. Their work enabled Moderna to include higher doses of vaccine in its shots. In early 2020, Moderna developed Covid-19 shots that included 100 micrograms of vaccine, compared with 30 micrograms in the Pfizer-BioNTech vaccine. That difference appears to help the Moderna vaccine generate higher titers and provide more protection.
"You set out in a career in drug discovery to want to make a difference," Benenato says. "Seeing it come to reality has been surreal and emotional."
Editor's Note: This essay is excerpted from A SHOT TO SAVE THE WORLD: The Inside Story of the Life-or-Death Race for a COVID-19 Vaccine by Gregory Zuckerman, now on sale from Portfolio/Penguin.
*Jason Schrum's arthritis is now in complete remission, thanks to Humira (adalimumab), a TNF-alpha blocker.
The Next 100 Years of Scientific Progress Could Look Like This
In just 100 years, scientific breakthroughs could completely transform humanity and our planet for the better. Here's a glimpse at what our future may hold.
The Next 100 Years of Scientific Progress
Kira Peikoff was the editor-in-chief of Leaps.org from 2017 to 2021. As a journalist, her work has appeared in The New York Times, Newsweek, Nautilus, Popular Mechanics, The New York Academy of Sciences, and other outlets. She is also the author of four suspense novels that explore controversial issues arising from scientific innovation: Living Proof, No Time to Die, Die Again Tomorrow, and Mother Knows Best. Peikoff holds a B.A. in Journalism from New York University and an M.S. in Bioethics from Columbia University. She lives in New Jersey with her husband and two young sons. Follow her on Twitter @KiraPeikoff.