Scientists Jason Schrum and Kerry Benenato solved crucial challenges in mRNA vaccine development.
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.
Rakhi Patel is among an increasing number of health care professionals, including doctors and nurses, who maintain an active persona on Instagram, TikTok and other social media sites.
“Health care professionals are quite prevalent on social media,” said Mercer Gary, a postdoctoral researcher at The Hastings Center, an independent bioethics research institute in Garrison, New York. “They’ve been posting on #medTwitter for many years, mainly to communicate with one another, but, of course, anyone can see the threads. Most recently, doctors and nurses have become a presence on TikTok.”
On social media, many health care providers perceive themselves to be “humanizing” their profession by coming across as more approachable — “reminding patients that providers are people and workers, as well as repositories of medical expertise,” Gary said. As a result, she noted that patients who are often intimidated by clinicians may feel comfortable enough to overcome barriers to scheduling health care appointments. The use of TikTok in particular may help doctors and nurses connect with younger followers.
When health care providers post on social media, they must bear in mind that they have legal and ethical duties to their patients, profession and society, said Elizabeth Levy, founder and director of Physicians for Justice.
While enduring three years of pandemic conditions, many health care professionals have struggled with burnout, exhaustion and moral distress. “Much health care provider content on social media seeks to expose the difficulties of the work,” Gary added. “TikTok and Instagram reels have shown health care providers crying after losing a patient or exhausted after a night shift in the emergency department.”
A study conducted in Beijing, China and published last year found that TikTok is the world’s most rapidly growing video application, amassing 1.6 billion users in 2021. “More and more patients are searching for information on genitourinary cancers via TikTok,” the study’s authors wrote in Frontiers in Oncology, referring to cancers of the urinary tracts and male reproductive organs. Among the 61 sample videos examined by the researchers, health care practitioners contributed the content in 29, or 47 percent, of them. Yet, 22 posts, 36 percent, were misinformative, mostly due to outdated information.
More than half of the videos offered good content on disease symptoms and examinations. The authors concluded that “most videos on genitourinary cancers on TikTok are of poor to medium quality and reliability. However, videos posted by media agencies enjoyed great public attention and interaction. Medical practitioners could improve the video quality by cooperating with media agencies and avoiding unexplained terminologies.”
When health care providers post on social media, they must bear in mind that they have legal and ethical duties to their patients, profession and society, said Elizabeth Levy, founder and director of Physicians for Justice in Irvine, Calif., a nonprofit network of volunteer physicians partnering with public interest lawyers to address the social determinants of health.
“Providers are also responsible for understanding the mechanics of their posts,” such as who can see these messages and how long they stay up, Levy said. As a starting point for figuring what’s acceptable, providers could look at social media guidelines put out by their professional associations. Even beyond that, though, they must exercise prudent judgment. “As social media continues to evolve, providers will also need to stay updated with the changing risks and benefits of participation.”
Patients often research their providers online, so finding them on social media can help inform about values and approaches to care, said M. Sara Rosenthal, a professor and founding director of the program for bioethics and chair of the hospital ethics committee at the University of Kentucky College of Medicine.
Health care providers’ posts on social media also could promote patient education. They can advance informed consent and help patients navigate the risks and benefits of various treatments or preventive options. However, providers could violate ethical principles if they espouse “harmful, risky or questionable therapies or medical advice that is contrary to clinical practice guidelines or accepted standards of care,” Rosenthal said.
Inappropriate self-disclosure also can affect a provider’s reputation, said Kelly Michelson, a professor of pediatrics and director of the Center for Bioethics and Medical Humanities at Northwestern University’s Feinberg School of Medicine. A clinician’s obligations to professionalism extend beyond those moments when they are directly taking care of their patients, she said. “Many experts recommend against clinicians ‘friending’ patients or the families on social media because it blurs the patient-clinician boundary.”
Meanwhile, clinicians need to adhere closely to confidentiality. In sharing a patient’s case online for educational purposes, safeguarding identity becomes paramount. Removing names and changing minor details is insufficient, Michelson said.
“The patient-clinician relationship is sacred, and it can only be effective if patients have 100 percent confidence that all that happens with their clinician is kept in the strictest of confidence,” she said, adding that health care providers also should avoid obtaining information about their patients from social media because it can lead to bias and risk jeopardizing objectivity.
Academic clinicians can use social media as a recruitment tool to expand the pool of research participants for their studies, Michelson said. Because the majority of clinical research is conducted at academic medical centers, large segments of the population are excluded. “This affects the quality of the data and knowledge we gain from research,” she said.
Don S. Dizon, a professor of medicine and surgery at the Warren Alpert Medical School of Brown University in Providence, Rhode Island, uses LinkedIn and Doximity, as well as Twitter, Instagram, TikTok, Facebook, and most recently, YouTube and Post. He’s on Twitter nearly every day, where he interacts with the oncology community and his medical colleagues.
Also, he said, “I really like Instagram. It’s where you will see a hybrid of who I am professionally and personally. I’ve become comfortable sharing both up to a limit, but where else can I combine my appreciation of clothes with my professional life?” On that site, he’s seen sporting shirts with polka dots or stripes and an occasional bow-tie. He also posts photos of his cats.
Don S. Dizon, a professor of medicine and surgery at Brown, started using TikTok several years ago, telling medical stories in short-form videos.
Don S. Dizon
Dizon started using TikTok several years ago, telling medical stories in short-form videos. He may talk about an inspirational patient, his views on end-of-life care and death, or memories of people who have passed. But he is careful not to divulge any details that would identify anyone.
Recently, some people have become his patients after viewing his content on social media or on the Internet in general, which he clearly states isn’t a forum for medical advice. “In both situations, they are so much more relaxed when we meet, because it’s as if they have a sense of who I am as a person,” Dizon said. “I think that has helped so much in talking through a cancer diagnosis and a treatment plan, and yes, even discussions about prognosis.”
He also posts about equity and diversity. “I have found myself more likely to repost or react to issues that are inherently political, including racism, homophobia, transphobia and lack-of-access issues, because medicine is not isolated from society, and I truly believe that medicine is a social justice issue,” said Dizon, who is vice chair of diversity, equity, inclusion and professional integrity at the SWOG Cancer Research Network.
Through it all, Dizon likes “to break through the notion of doctor as infallible and all-knowing, the doctor as deity,” he said. “Humanizing what I do, especially in oncology, is something that challenges me on social media, and I appreciate the opportunities to do it on TikTok.”
Previous research showed that restricting calories results in longer lives for mice, worms and flies. A new study by Columbia University researchers applied those findings to people. But what does this paper actually show?
Evan Hadley, Director of the Division of Geriatrics and Clinical Gerontology at the National Institute of Aging
NIA