Interview with the 2023 Nobel Prize laureate in physiology or medicine Katalin Karikó on 6 December 2023 during the Nobel Week in Stockholm, Sweden.

What brought you to science?

Katalin Karikó: Honestly, I have to say my high school teacher, who said that ‘You could be a scientist’, and he said it so many times that at the end I believed it and I imagined myself that I will be a scientist and imagine going to work and every day figure out something. I had never seen a scientist, I grew up in a very small town, and I decided that I will be a scientist. Somebody is believing in you, maybe that’s the inspiration.

What do you enjoy most about science?

Katalin Karikó: Science is fun, to be a scientist, this is a fun job. What is exciting is that there is a complexity, and then it is you who can solve it by reading articles or doing experiments and put together things which maybe nobody did. Then you realise what’s going on. The joy that you were the first one to know that this is how things happens. That’s one. It is very similar to be like a detective or an investigator on a crime, but the end of it, you don’t find a perpetrator, you find a solution, and maybe that solution would help somebody. That’s what is the beauty about it, maybe somebody who’s sick and then your discovery can contribute to their healing.

How have you maintained your focus despite all the obstacles you have faced?

Katalin Karikó: I have to say that people judged me unsuccessful when I felt very successful, because in the laboratory I was in full control of doing experiment, getting question asked and then getting the answer for it. Of course, you never get the answer because when you do an experiment, you get more questions instead of the answer. But this is what is exciting. It seems that not getting funded and there are other difficulties. But actually, when you are a scientist, you constantly have to fight the failures and solve problem difficulties. You keep repeating, you don’t understand, so it is like scientists are those who can get up and keep working with the same enthusiasm. That’s actually some defined success that you can stand up and you can keep on with the same enthusiasm as before.

What advice do you usually share with young scientists when they are facing obstacles?

Katalin Karikó: I have seen that the young scientists are comparing themself to the others, seeing that they are maybe less hard workers, and they are advancing. I say, ‘Don’t do that. You have to focus on what you can do’. If you already took away your attention and paying attention on somebody else, you won’t succeed. You have to focus on what you can do, what your project is. I also tell them, to be a scientist is not for everybody. If you like to follow instructions, maybe you have to go to the military. You like to be in the spotlight, like I am right now, you have to be an actress or maybe a reporter. Because a scientist is usually thinking in the laboratory and is not in the spotlight like I am. You have to enjoy no matter what kind of work you are doing. That’s the most important.

I tell them also that physical and mental health is very critical. I used to exercise every morning. I was running six kilometres, even when, 10 years ago, I worked in Germany and on the Rhine, I ran six kilometres, once I even ran the marathon. I was 50 years old, I set up the goal to make it, and that’s it. You have to learn how to handle stress. That’s also very important. I was very lucky that I learned from Hans Selye who was Hungarian, and he was studying stress. In Hungary, when I was 16 years old, I read his book and learned how to handle it. The mantra is, I can tell the young one – and even the old one if they don’t know about it – is that you have to focus on what you can do. Not that what your boss should do, your wife should do, your neighbour should be quiet or something. You have to decide what you can do about that, that’s what is taking away all of the stress.

Was there a specific mentor who influenced your career?

Katalin Karikó: My father was a butcher, and I heard that when I was little, I was curious when he opened the pig, and I want to see what is inside, whereas my sister and my mother did not want to see that. I don’t remember that, but they said that I was standing there seeing that now, this animal was moving, now, it’s not moving, what made this animal move? I don’t know, but definitely the teachers. I am very grateful to them, because in elementary school already we had excellent teachers, and we went to … Like with the biologic teacher, we just went to outside in the fall, and he picked up the leaves and said, ‘Oh, it is yellow. Is it the yellow it became because it was green before, or maybe the yellow was behind the green and the green is gone?’ He made us think, ‘Hm, or the red leaves, where is the red coming from?’ I am very grateful to them. In elementary school I already competed in different biologic competitions, and at eighth grade, I was the third best in Hungary.

How was it to visit your home country Hungary after the Nobel Prize announcement?

Katalin Karikó: When I went back to Hungary, to my alma mater, it was a beautiful sunny day, and several hundred people were there and they were cheering, and I was just so surprised. Then in the evening a few thousands were there and every time they said, ‘Say something’ and in the moment, I just remember that when the announcement was made, and on that day we went to the university, there was a flash mob. After that Drew Weissman went to his team to celebrate, I went home. Then I told the people there who were waiting, in Hungary, I told them, ‘Now, I am here. I want to celebrate with you’. Because the city Szeged also is very important because I studied there for five years, and that was one time I met my husband there, we married, my daughter was born in Szeged. All the happy times that I was in this city, so happiness belonged to that city. I told them so, and they were cheering to any word I said, they were cheering.

What do you plan to do with your prize money?

Katalin Karikó: It is most likely I will spend the money for education and helping students. I don’t really like to brag about things, but all the award I got in Hungary, I never took out from the country. I gave to organisations helping underprivileged children. I, myself benefited from that because my parents had just elementary school education and going to the university, even getting a high school diploma I was in the first in the family. My sister also got a high school diploma and she also got a PhD in economic, but we were from there. I think that those children whose parents may be not educated enough to see that the future brightness of their children should be followed up in higher education. There are programs there, so I gave money for that. Also at the university, my alma mater, University Szeged, some prize money I channelled there. Even other awards, like Princess of Asturias, to the local kids I gave the money back.

How was it to move from Hungary to the US?

Katalin Karikó: I was born 68 years ago in Hungary, and up until I was 30 years old I was living in Hungary. I got my education, my PhD, I started research on RNA, even lipids, I did study. Moving to the United States was not easy because I lost my position in Hungary. I tried to find a job in Europe and I applied for a couple of jobs, but I couldn’t apply for finance because we were behind the Iron Curtain and eventually, I had to go all the way to America. I am one of those scientists, I never dreamed about going to America. Everybody was talking, ‘Oh, America’. I was very happy in Hungary, but I had to go. I ended up in Philadelphia, and the system was at that time in the communist Hungary that you are allowed to leave the country with $50 per person, and because I got a job offer, I even was not eligible for the $50. The family, my daughter was two and a half years old, my husband, we had a hundred dollar, so that was difficult to imagine that we are arriving and for one month how we will survive. We had a Russian-made car, and that we sold to my colleague, and then on the black market, we exchanged the Hungarian currency to pound. We got like 800 pounds because they had just pounds, not the dollar, and that’s what we got. That’s how we started in America. Imagine that you go there in 1985, you don’t have a credit card, you have no cell phone, iPhone, we didn’t have any, at that time nobody had. I had nobody there I knew, no family member ever got to America and then no classmate, no teacher, nobody. You just have to learn so quickly how to survive.

What was your first impression of the US?

Katalin Karikó: It was a cultural shock. When arriving immediately they said, ‘Now you have to select a bank’. I said, ‘Why? I don’t need a bank. I never had in Hungary, a bank’. They said, ‘How did you get the salary?’ I said, ‘Oh, it was in an envelope. It was counted all of the last pennies in it’. They said, ‘Oh, we don’t do that’. Everything was a shock because going from Hungary today to there would be very different. But in 1985, it was unbelievable.

What does Hungary mean to you today?

Katalin Karikó: I grew up there, my sister lives there, my mother, she passed away five years ago, but she lived there, I have relatives there and I grew up there. But of course, that Hungary which I left is very different now. I have to say that when I worked the last 10 years in Germany, I felt in Germany more a Hungarian. I could see things there that reminded me of my home. Of course I am happy to go back and talk to fellow scientists and meet my colleagues and fellow students, but it is different. That’s the same way even for United States, because when I was working in Germany and going back, now I go back to University of Pennsylvania, I worked there for 24 years. I worked there, and I don’t know the people, they are changed. Of course the campus also changed a lot.

Tell us about your co-laureate Drew Weissman and your collaboration.

Katalin Karikó: I used to work at the cardiology department, which belonged to the cardiology section, which belonged to the department of medicine. But then from there, I moved to the surgery department, which is a different building, an adjacent building, but I know the code for the Xerox machine only in the medicine. Surgery, where I worked, had no Xerox machine, and we always had to Xerox copy the scientific articles. I keep going back to the prior place, and then I could see this guy I had never seen before. I introduced myself because I kind of like to brag and I told him what I am doing while he was xeroxing. He’s very quiet, so I mentioned him that I work with mRNA, and he said that he came from Anthony Fauci’s lab. At that time it didn’t ring any bell for me, for Fauci was not in the television all the time. Then he said that he wanted to make a therapeutic or prophylactic vaccine for HIV, and we started to talk more. I told him that I can make mRNA for him. He gave me the genes and I cloned and I made RNA and we started to work together. So it is true, we met at the Xerox machine, but that part that we were wrestling and fighting, that was not true. We looked at the data, scientific results, then we were not different. We cut each other words, what does it mean, what we should do, no, we should do that, we were talking like that. But otherwise, he’s quiet more, according to his wife he has a limited number of words he can say one day, and when he goes home, he already used up all. He’s a physician, so when we looked at some data, he was thinking about some disease-related thing, and I was more thinking about the basic science because I am a biochemist. We educated each other. I learned from modern immunology vaccinology from him, and he learned the RNA part. That’s one thing, that where the innovation can come. You might have a big team and you are investigating some phenomenon from many different directions, huge team can do that. Or there are two persons who are on different fields, they understand each other, they respect each other and educate and then they come up with something. Oh, I can do that, I can do. Then they proceed.

What advice would you like to share with young scientists?

Katalin Karikó: The number one thing: you have to enjoy what you are doing. It is important. You have to realise that you like the things, what you have to do in the rest of your life, as if you select as a job. I mentioned the health is important because you remember the airplane, you have to use the oxygen first on you. If you are not okay, then you cannot help others. You have to be happy, healthy, and stressless. You have to take care of yourself and then you can help others. The young ones, we can go on and on how many things I could tell them about how they should proceed, but the most important thing is that they have to enjoy what they are doing. I have to say what is important if they decide they will be scientists. What I could see is that you have to solve a problem. You are working on this problem. What is the thing is that you publish because you’ve discovered something, and then somehow you want more discovery, more money is needed, applying for fund. Then finally somehow publication is coming because we need more money, we need the promotion, and the goal will be somehow is advancing your career to promote tuition and other things, and the prestige, and somehow the original goal becomes a tool to reach that. You are publishing because you have to get your PhD degree, you need more grant, more money. If you stay with the focus on solving scientific problems, you’ll never be disappointed. When you move to this one and you don’t get the promotion, then you’ll get the disappointment because this will not depend on you, maybe on some other organisation or superiority. But here the problem is always there, you can always work on it.

Is diversity important in science?

Katalin Karikó: It is important in science to have women because we are thinking differently. We are multitasking, guys cannot do that very well. People have different views, different thinking as I mentioned, like somebody’s a physician or there is a basic scientist and they are thinking differently. If they work together and respect each other, then a new invention can be done. That’s what I think is important, so I try to emphasize that women are important for science, and the science need more women because at the beginning there are many women graduating schools and they have their dream, but the difficulties might come when they have a childbearing age and they want family. I was lucky in Hungary because we had high quality, affordable childcare, so I could stay at work and I was confident that my daughter was taken care of when I was working. I can see in many countries that if you are not having enough financial support, then you have to give up your job because that little baby is crying there and you have to take care of it. Your dream is just a potential, giving up seems a solution to take care of your child. But if a government is listening, then we have to talk to them how important that would be because more women could do more discoveries,

Do you see any similarities between sports and science?

Katalin Karikó: It is kind of like setting of a goal. When I was practicing for the marathon, my daughter was biking next to me, ‘Mom, come on, come on, you can do it, you can’. Even when it was the race, she volunteered to give out water, hardly could wait when I will reach that water stand so she can give me the water. The race was in November, in March I started to practice. You are not getting up in one day, ‘Okay, today I run a marathon’ – you will be dead, you cannot run. She could learn that you have to do the preparation every day, do something towards that goal. That’s what setting up goals is what is important, for everybody, a child, old people, everybody has to have a goal and then work towards that and when you reach that, you are setting up a new goal. That’s like they told me, that you get a Nobel Prize, and that’s what you can do after that. I mean, that’s not a goal. A goal is that I am doing my research and then when I am done with certain things, then I set up a new goal – it cannot be a goal to get an award, because anyway it does not depend on me. I told that always I have to focus on what I can do, and those are other people’s decision. That’s for the firing and terminating my position. I also said that it was other people’s decision and I have to focus on what I can do instead of feeling sorry for myself Why me? There were other people could be fired. Why me? No, don’t spend your time because you are feeling down and feeling sorry for yourself. You focus on, okay, now what should I do? Because  you can make a decision, and that’s what important. I mentioned that it is not necessary that you have to be happy if you are terminated in a position. I was not happy, but did not spend time on being sad, but I have to do something next.

When did you learn the importance of setting up goals?

In the process, as I mentioned, in elementary school when I was writing about Linné, it was for the high school advertise that you can write an essay. Every day I was reading something, writing something, and you work towards and submitting that essay. That’s already the win. I never get any award for that, and that is not important. I set up a goal and accomplish, and then the next goal to set up, and maybe my daughter, watching me, learn that. That’s what I say to also the parents. You don’t have to over assist your child; they like to be independent. Rather than what you are showing that you go to work, what is important, how you talk to other people, that’s what they watch. They could learn from that. You can tell them certain things and they can see that you are acting differently. They notice that and they will take on that. So, if you work hard and you enjoy your work and your child want to do that also.

Did you realise how important your research would be during the COVID-19 pandemic?

Katalin Karikó: I worked at BioNTech and BioNTech signed with Pfizer in 2018 to develop mRNA-based vaccine for influenza. We already worked two years, -18 and -19, and we did all of the studies and were ready for start a human trial for influenza. The technology is such that you just have to change – I should say just, but, still is a process – change template and then you can make the different kind of vaccine, and that’s what happened. We were ready with all of this preparation for another fight, another disease. But here we had to have prophylactic vaccine for the sars covid 2, and the influenza was ready, so a lot of preparation was done for a different virus, but it is now, it’s phase three trial. The vaccine for influenza is very important that the RNA, because it is always from the four nucleotides, contains the four nucleotides, so we can have a multivalent vaccine. The influenza, again, influenza A and B and different many different proteins encoding RNA can be in one shot. Right now, not even just the influenza, but even the covid vaccine and respiratory CCR virus, it’s one shot because you can combine them. If it would be protein based, you cannot do that because they will stick to each other and then will have an aggregate because the protein can be charged negative, positive or hydrophobic hydrophilic, and you cannot mix them. But the RNA, you can do it and the subject will synthesise the protein, and then those proteins will teach the immune system. That’s what the enemy is, you have to recognise.

How does it feel to know that your research has saved millions of lives?

Katalin Karikó: I have to say that I myself, I never felt that I did. I relied on the work on many other people, I was doing research for 20, 30 years. I learned from reading articles from people who are not with us anymore, and I learned from it. I had colleagues and so many, many people who contributed. I feel that we did it. We scientists, with all of my colleagues at Pfizer, BioNTech as well as University Pennsylvania, and those scientists who worked on the field. That’s how I feel, and I have to say, I was lucky. I never had this craving of recognition. There are some people who want to be recognised. For me, it was enough that I know that what I did and what is important and not that other people would know. For me, I feel that a lot of scientists, hundreds and thousands of scientists, contributed to the knowledge, because the RNA was discovered 60 years ago, and during those 60 years, many things happened. I will present that on my presentation and the Nobel presentation lecture. I will tell you that how many things was discovered and was contributed by scientists. As a scientist, I felt that I didn’t expect it that what I am doing will be that important. I know that it is important. I know that one day maybe other scientists will take on and reaching in one day a level that somebody will be helped.

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