Katalin Karikó: The Unsung Hero of mRNA Vaccines

　　On October 2, 2023, the 2023 Nobel Prize in Physiology or Medicine was awarded in an “unpopular way” to a hot topic-a scientific discovery that made a breakthrough contribution to the development of the mRNA COVID-19 vaccine.
　　More often than not, the awarding of the Nobel Prize is controversial due to its delayed nature. The Nobel Prize is willing to wait until it is confirmed that a scientific achievement has withstood the test of time.
　　But this time the Nobel Prize received a rare swift response: it was awarded to Katalin Karikó of the German biotechnology company BioNTech and Drew Weissman, a professor at the University of Pennsylvania, ” In recognition of their discoveries in nucleoside base modification, which enabled the development of an mRNA vaccine against COVID-19.”
　　From another perspective, this time the winner is also an “unpopular” candidate: Carrico is the 13th female scientist to win the Nobel Prize.
　　This Hungarian woman’s enthusiasm for the mRNA molecule and her extraordinary persistence have been looked down upon in academic circles for a long time. Looking back on her life in the United States after traveling across the ocean for more than 30 years, she has only one goal: to promote the application of synthetic mRNA in human cells. Because of this non-mainstream and unpopular molecular research, she was unable to obtain scientific research funds for a long time and was kicked away by various scientific research groups like a football.
　　But Carrico is happy to immerse himself in his own world of mRNA. She was fired from the University of Pennsylvania 10 years ago, where she had worked for more than 20 years, and then went to Germany to do her own experiments, re-cultivate plasmids, and sow cells.
　　It wasn’t until the COVID-19 pandemic that Carrico’s passion and perseverance finally became visible. The research of two scientists tells the world that small mRNA can quickly guide human cells to create their own protective umbrella.
　　Supporting this female scientist is her husband and two-time Olympic rowing champion, her daughter Susan. When receiving the notification call for the Nobel Prize, Carrico said: “As a woman and a mother, I want to say to female scientists that you don’t have to choose between family and work, and you don’t have to take too much care of your children. What you do counts. What’s important is that she will regard you as a role model.”
　　The path that is not favored by the mainstream and the gender that is still in the minority in the spotlight has finally come to save the world.
　　Genius Perseverance In
　　 1955, Kaliko was born in a small town in Hungary. His father was a butcher and his mother was a librarian. Although his family was not wealthy, Carrico had been interested in science since he was a child, and he determined to become a scientist at that time.
　　 She got excellent grades and later entered the University of Szeged, a well-known university, and received a PhD in biochemistry. Later, he entered the Hungarian Biological Research Center and continued to engage in research in the field of biochemistry. Her main research direction at that time was mRNA, but after working for a long time, there was no breakthrough and no other research results.
　　 The good times did not last long. In 1985, her laboratory suddenly lost funding, and Carrico had no way out. After many efforts, she decided to move her husband and daughter to the United States to continue her studies. Her dreams became more concrete. A bold guess about mRNA is waiting to be proven.
　　When moving to a foreign country, Carrico’s future was uncertain. What also cast a shadow over this future was the foreign exchange control policy adopted by the Hungarian authorities at the time, which only allowed outbound travelers to bring a maximum of US$100. Carrico sewed all his assets, $900, into his daughter’s bear doll, and then flew out of the country with the bear.
　　When she arrived in the United States in 1985, she had no credit card, no mobile phone, and no relatives or friends in the United States. She only focused on research. She later said: “In Hungary, if there is a shortage of a certain chemical, we try to find out how to make it, instead of saying, ‘We can’t order that thing.'” At this time, mRNA research was internationally recognized
　　. Many breakthrough results. Messenger RNA (mRNA) was first discovered by French scientists in 1961. Soon, researchers figured out the rules of genetic information: human cells use double-stranded deoxyribonucleic acid DNA as a template to produce single-stranded ribonucleic acid RNA through transcription, and then use messenger RNA (mRNA) as a template to express proteins.
　　This messenger specifically oversees the assembly of specific proteins. In other words, if you know the mRNA sequence, you can determine the protein information.
　　With this premise in mind, the scientific community began to have bolder ideas: If humans could synthesize mRNA in reverse, could it induce the production of specific proteins in the body?
　　Carrico is a firm believer in the power of small molecules to make a big difference, especially when used in vaccines.
　　After all, protein is closely linked to the body’s immune system. Viral proteins can activate the body’s immune response.
　　Imagine that the virus’s mRNA encoding is first injected into the human body to induce the production of virus proteins in the body. The immune system then kicks in, producing antibodies in advance. In this way, when the real virus comes, the human body will be well prepared.
　　This was a path that immunology had never imagined at the time. In the past 300 years of vaccine history, only a small amount of virus was injected into the body outside the body to trigger the immune system to kill and reduce the virus. Or viruses that change their chemical structure may be injected into the body to train the immune system to resist the virus. No one has thought about letting the human body produce viruses on its own.
　　Almost no one understood this seemingly seamless logic at the time.
　　Cardiologist Elliot Barnason, Carrico’s first collaborator at the University of Pennsylvania, remembers that “most people laughed at us” when he and Carrico tried to implant mRNA into cells. This research made some progress, but it ended with Barnason giving up his teaching position and jumping into a company.
　　Carrico drifted into the second laboratory. She still insisted on using mRNA to implant cells, hoping to trigger an immune response from the vector, but this time it still failed. The collaborator switched jobs to another biological company, and even the department director also resigned.
　　 It was a period of time that Carrico could not look back on. She was demoted from professor to researcher, was also diagnosed with cancer, and her husband was trapped in Hungary due to a visa. The mRNA technology she invested a lot of energy in research has reached the point where it is unsustainable.
　　These failures have repeatedly confirmed the judgment of ordinary researchers: mRNA cannot guarantee safety; it is difficult to stimulate cells to produce large amounts of protein, and its effectiveness is also worrying.
　　For a long time, greatness only stayed in imagination, in her brain.
　　”Don’t bother.”
　　Destiny always changes in those inadvertent moments.
　　At Penn, Carrico, who was struggling with zero funding, could not let go of the excitement that the beauty of mRNA would bring to people in the future. The imagination of nucleic acid therapy attracted her like a black hole. The natural convenience—the ability to stimulate the immune system to act in advance by mastering only a viral sequence—seduced her and made her unable not to devote herself to it. At that time, Kaliko was like a lone brave man in the darkness.
　　In 1997, Carrico was demoted for being too obsessed with the underappreciated mRNA. At this time, while waiting at the copier to print journal articles, she met Weisman, a new faculty member in the medical school.

　　”I’m an RNA scientist and I can make anything with mRNA.” she told the other party.
　　Weisman said he is committed to developing an HIV vaccine. In response, Carrico replied: “Yes, yes, I can do it (with mRNA).”
　　The two hit it off. Carrico joined Weisman’s team as a low-level researcher.
　　But these were still years of failure. She has achieved artificial production of mRNA molecules. Her idea also worked well in a culture dish, and the cells actually produced the protein she wanted. However, once the mRNA was injected into living mice, everything went out of order again.
　　”All we saw was that the mice were sick. They had matted fur, curled up, stopped eating, stopped running,” Weisman recalled.
　　The direction of Weissman and Carrico’s research became how to make the mRNA escape the surveillance of the immune system when it enters the carrier and no longer trigger a strong immune response.
　　The adventure with mRNA, accompanied by his own obsession, kept Carrico distracted all day long. She received a very low salary, but spent all day in the laboratory. Her husband also calculated for her that if the hourly wage was calculated, “Carico’s hourly wage would be only $1.”
　　It was not until a control group experiment that the two finally discovered that when their own mRNA injection triggered an overreaction of the immune system, the control group was injected with another form of RNA, tRNA, in the vector, and no inflammatory reaction occurred.
　　The longed-for answer emerged. A molecule in tRNA called pseudouridine plays a role in helping the nucleic acid injected into the carrier avoid immune reactions.
　　They finally understood that mRNA is a single-stranded structure composed of four kinds of nucleotides arranged in different orders. The difference between the four types of nucleotides lies in the different nucleoside bases. Among them, a base called uracil has become the key to the problem.
　　It has two ways of connecting with ribose. Under normal circumstances, it forms uridine, but under special circumstances, it can also form pseudouridine. As long as pseudouridine is used instead of uridine to form modified mRNA, it can effectively avoid the surveillance of the immune system.
　　Not only that, this pseudouridine can also make the function of mRNA more powerful, directing each cell to synthesize 10 times more protein.
　　In other words, injecting this technology into the carrier ensures safety and effectiveness.
　　The two of them had been researching hard and found a solution in the endless darkness.
　　In 2005, Weisman and Carrico published the results of this new technology, which they believed had the potential to change medicine, in the journal Immunity.
　　A confident Weisman told his juniors that after publication, “our phones will definitely be ringing off the hook.”
　　As a result, “nothing happened,” Carrico recalled. “We didn’t receive a single call.” The turning
　　point in the fate of the medical community, the attention that should have poured in, was all just imagination. When discussing vaccines, what people mention is the inactivated and attenuated vaccines that have saved mankind from fire and water for 300 years.
　　“We were both applying for grants at the time,” Weisman recalled. As a result, “people weren’t interested in mRNA. The people reviewing the funding said, ‘mRNA is not going to be a good treatment, so don’t bother.'” Fighting to Fame The story isn’t over
　　yet
　　.
　　If not for the COVID-19 pandemic, the two founders of modified mRNA technology would still be unknown.
　　Regarding the research on mRNA technology vaccines, only a few companies have taken notice. It is foreseeable that this is an area with huge investment but full of unknowns.
　　The pursuers of mRNA therapy are all targeting the “ceiling” of human diseases – cancer that has defeated countless families.
　　In 2010, clinical trials of Provenge, an mRNA vaccine used to treat prostate cancer, were launched for the first time. This type of cancer vaccine is different from the cervical cancer (HPV) vaccine, which is a preventive vaccine, while the mRNA cancer vaccine is a therapeutic vaccine.
　　What researchers want to achieve is to give the vaccine one shot so that the patient’s immune system can learn to distinguish disguised tumor cells and eliminate the cancer cells.
　　The idea is wonderful, but the road to technological breakthroughs requires us to pull our feet out of the mud again and again. The Provenge vaccine did not bring the hoped-for results. Clinical trial results showed that it only extended the overall survival of prostate cancer patients by 4.1 months. Moreover, this vaccine is priced at US$93,000, which is far more than what ordinary people can afford.
　　The parent company that developed the cancer vaccine Provenge ended up in bankruptcy.
　　As for Weisman and Carrico, they founded the company RNARx in 2006. RNARx collapsed in 2010 due to factors such as running out of funds. In 2013, Carrico was fired from his teaching position at the University of Pennsylvania after failing to make any important academic achievements.
　　Their mRNA design is now even more in danger. There are still many places where we cannot break through. For example, cancer vaccines have always had a bottleneck. Cancer cells react differently in everyone, are highly specific, and become cancerous quickly.
　　How to select the tumor antigens with the highest frequency among many cancer cells to make the mRNA vaccine universal. This is difficult to do in lengthy clinical trials.
　　At the same time, the single-stranded structure of mRNA also caused problems in real experiments. mRNA is very unstable and not only needs to be stored at ultra-low temperatures, but is also easily degraded by extracellular RNases.
　　In the second decade of the 21st century, scientists decided to build a pathway for mRNA to reach cells.
　　Finally, with the joint efforts of Weissman, Carrico, British scientist Peter Kulis and others, lipid nanoparticles (LNP) were invented in 2015. This tiny nanobubble, like a dumpling wrapper, tightly wraps the mRNA, protecting it from being broken down and ultimately delivering it safely to the cell.
　　Also that year, the first mRNA influenza vaccine was tested using lipid nanoparticles.
　　Although at this time, this is still a technology that no one knows about at the public level.
　　Until the COVID-19 pandemic in 2020, all the previous efforts and precipitation were revealed in this epidemic. Using modified mRNA technology, the new coronavirus mRNA vaccine directly allows the coronavirus’s mRNA to enter the human body through rapid viral gene sequencing, instead of cultivating the virus in egg whites like the traditional method.
　　The mRNA vaccine, which is simple, fast and safe in the face of epidemic diseases, is finally known to the world.
　　Of course, the question still remains: It is also using mRNA technology. Why has the tumor vaccine been researched for several years without any results, but it has become famous in the new crown vaccine?
　　Yang Haitao, a former professor at the University of California, San Diego School of Medicine, once explained to reporters that this is related to the scale of clinical trials of the two vaccines.
　　Generally speaking, the scale of cancer treatment trials only involves dozens to hundreds of people. The sample size is not large enough, and the evaluation of safety and practical effects is not scientific and accurate enough.
　　”How difficult and expensive is it to find 30,000 cancer patients with the same condition, same age, and same living and eating habits around the world? But the purpose of the new coronavirus vaccine is prevention, and the selection conditions for clinical trial subjects are more relaxed. Phase III clinical trials can easily Expand to 30,000 people.”
　　Yang Haitao believes that the application of the new crown vaccine has accelerated the verification of the safety and practicality of the mRNA technology path, clearing obstacles for future tumor vaccine research and development, and the two “mutually achieve each other.”
　　The new crown vaccine has greatly increased confidence in the mRNA field. Moderna, which was the first to possess relevant technology, announced this year that it is developing a personalized tumor vaccine and expects it to be launched within five years. “It is expected that tumors will be eliminated with mRNA vaccines by the end of this century.”
　　Now, it is obvious that for Carrico and Weisman, who have spent their lives studying mRNA technology, the phones on the side will ring repeatedly.