Working like nothing happened

One room. No running water. No telephone, no TV. Katalin Karikó grew up in Kisújszállás, a town of about ten thousand in eastern Hungary, the four of them in a one-room cottage.

Water came from the middle of the street. "It was also the chat room," she said, "where you learned everything going on."

Her father was a butcher until he took part in the 1956 uprising. After that he lost the post and did odd jobs until he landed in a pub. "I could see that he was always coming up with a solution," she remembered. Her mother kept books. Neither parent had finished high school. "My parents encouraged us to study," she said, "because they had no opportunity."

She was small when she watched her father open a pig, standing there where the rest of the family looked away. "I wanted to see what is inside," she said. "They said that I was standing there, seeing that now this animal was moving, now it's not moving. What made this animal move?"

In school she got both kinds of teacher. One told her he would make sure she never got to university. She worked harder. Another told her, over and over, that she could be a scientist. "He said it so many times that at the end I believed it," she said. "Somebody is believing in you, maybe that's the inspiration."

There was also the biology teacher who walked the class outside in the fall, picked up a leaf, and asked them: is it yellow because it was green before, or was the yellow there behind the green all along? He made them think.

At thirteen she traveled alone across Hungary to a science summer camp, changing trains, then on foot, asking directions along the way. At fourteen she traveled alone again, to a national contest in Budapest, hoping the adult who was supposed to meet her would be there. Third place in the country in biology. A summer program for promising kids from blue-collar families got her into the University of Szeged. "It was like winning the lottery."

PhD in biochemistry, 1982. RNA next: the body's working instructions, the messages cells use to build proteins. Then the lab's money ran out, and her position in Hungary ended with it. She looked across Europe; the Iron Curtain made it hopeless. "I never dreamed about going to America," she said. "I was very happy in Hungary, but I had to go."

Communist Hungary allowed $50 per person out of the country. Because she had a job offer waiting, she wasn't eligible for even that. They left with $100. The car was sold on the black market; the proceeds, a little more than $1,000, went into the stuffing of their two-year-old daughter's teddy bear. Their whole fortune.

"You just have to learn so quickly how to survive," she said.

Philadelphia, 1985. Temple University, RNA trials against AIDS. Then a lab in Bethesda, learning molecular biology. Then, in 1989, Penn, where the next twenty-four years happened.

The idea she carried was simple, and at the time it sounded ridiculous. Cells read instructions and build proteins. Write a new instruction, slip it inside a cell, and the cell builds what the instruction says. mRNA as medicine. mRNA was dismissed back then as unstable and useless. Almost nobody believed it could work.

At Penn they put her in the cardiology section, under a doctor named Elliot Barnathan, on a research appointment with a five-year clock on it. The first proof came in mice. She injected mRNA into blood vessels, and fifteen minutes later there were proteins that hadn't been there before. She watched a dot-matrix printer feed out the next result, chk-chk-chk-chk-chk, and saw the instruction work again, many times over. "The cell was producing plentiful amounts of protein upon instruction," she said. "It was like magic."

The rest was money, and the money didn't come. Grants rejected her. Too risky, too slow. She published more slowly than others, on purpose: "I didn't want to be so eager to publish that I risked contaminating the scientific literature with dubious results."

At one presentation, she challenged a colleague's data, asking whether the "signal" was more than background. She was asked not to attend those meetings anymore.

Then came 1995. Breast cancer in January. A husband stuck in Hungary over visa problems. And the five-year clock running out, with the university offering demotion or the door. She took the demotion and stayed at the bench. "Working like nothing happened," she has called it. She would say later that she was demoted four times.

Then, 1997: the photocopier. She had moved to the neurosurgery department, in the building next door, which had no copier, so she kept walking back to the old one. "One day I was photocopying research papers at a Xerox machine," she said, "and by chance I met Drew Weissman." (One version has the two of them wrestling for the machine. "We didn't wrestle with each other to get access to the copy machine," she said. "It is a made-up story.")

Weissman had come from Anthony Fauci's lab, and he wanted to build an HIV vaccine. She told him she could make the mRNA for him. He gave her the genes. She cloned them, made the RNA, and they started to work together.

The obstacle was the one that had killed every mRNA idea before theirs. The body raised an alarm at synthetic mRNA: inflammation, sick mice, sometimes dead mice. But the body's own RNA carried small chemical marks that the lab-made version didn't. What if they added the marks? They built the variants and tested them. One swap, uridine for a variant called pseudouridine, silenced the alarm and, strangely, raised the output. "We realised at that moment that this would be very important," she said.

They published in 2005, in the journal Immunity, and waited for the world to call. "We thought the phone would be ringing off the hook," she said. "But nothing happened. The phone didn't ring. Nobody cared."

The silence lasted years. In 2009 she asked to be reinstated on the faculty. They told her that they'd had a meeting and concluded she was "not of faculty quality." In 2013, after twenty-four years, she was out. "No goodbye party, nothing, just get out," she said. "I walked to the parking lot, thinking what next?"

"I was not happy," she said of the firing. "But I did not spend time on being sad. I had to do something next."

The next thing was BioNTech: a small German mRNA company that didn't even have a website yet. Her one condition for joining was that she could keep her research on modified nucleosides. She became a vice president, then spent seven years commuting between Philadelphia and Mainz. "It was more meaningful than more paperwork and more references," she said.

Then came the virus. She made it home on Friday, March 13, 2020, on one of the very last flights before everything locked down. Her husband's 60th birthday. The day the United States declared a national emergency. The vaccines that went into arms that December carried the fix she and Weissman had found: the modified message, inside a fatty bubble. A 2025 study in JAMA Health Forum estimated the vaccines averted more than 2.5 million deaths worldwide by late 2024.

October 2023: the Nobel Prize in Physiology or Medicine, shared with Weissman. She was 68. "I never had this craving for recognition," she said. "For me, it's enough that I know what I did." At the banquet in Stockholm she thanked her family, her teachers, her fellow scientists. And later, she thanked the other ones too: "I also thank the people who tried to make my life miserable, because they made me work harder and become more resilient."

The letter she talks about most came from a retirement home. A resident had tested positive; everyone braced to lose a third of the residents. They had been vaccinated the week before, and everyone lived. The home threw a party and sent her the pictures. "I can tell you that it was more important than any award," she said, "including the Nobel Prize. Reading that letter, seeing those pictures."

She ran a marathon at fifty, starting to train in March for a race in November. Her daughter bicycled alongside her through the long practices. "Mom, come on, come on, you can do it," she would call. On race day her daughter volunteered at a water stand and could hardly wait for her mother to reach it. "You cannot get up one day and say, okay, today I run a marathon," Karikó said. "You have to do the preparation every day."

She is 71 now. Back at Szeged, her first university, as a professor. Her prize money funds RNA research and students like the girl she used to be. Her advice to young scientists hasn't changed since she was one: "Focus on what you can do." Not what your boss should do. Not what your neighbor should do. What you can do.

"People judged me unsuccessful when I felt very successful," she said once. "In the laboratory I was in full control."

That was the one verdict nobody could take: the answers in the lab were still the answers, the next question was always waiting, and she kept going in. Working like nothing happened.

The phone didn't ring for years. When it finally rang, it was for everyone.