Katalin Karikó
Biochemist whose work enabled mRNA vaccines against COVID-19.
Katalin "Kati" Karikó (born 17 January 1955) is a Hungarian and American biochemist who specializes in ribonucleic acid (RNA)-mediated mechanisms, particularly in vitro-transcribed messenger RNA (mRNA) for protein replacement therapy. She laid the scientific groundwork for mRNA vaccines, overcoming major obstacles and skepticism in the scientific community, and received the Nobel Prize in Physiology or Medicine in 2023 along with American immunologist Drew Weissman.
- born
- 17 January 1955
- field
- Biochemistry
- nationality
- Hungarian and American
- known_for
- Nucleoside modifications that suppress immunogenicity of RNA; foundational work
- awards
- Nobel Prize in Physiology or Medicine (2023), Lasker–DeBakey Clinical Medical Re
Verified Timeline
Lore & Background
After postdoctoral work at Temple University and a brief position at the Uniformed Services University of the Health Sciences, Karikó was hired by the University of Pennsylvania in 1989. Despite initial support, mRNA fell out of favor, and after repeated grant rejections the university demoted her in 1995; she was never granted tenure. In 1997, she met Drew Weissman, and they began collaborating. Their key finding—that replacing uridine with pseudouridine in mRNA renders it non-immunogenic—was rejected by Nature and Science but accepted by Immunity. They also developed a delivery technique using lipid nanoparticles. Karikó co-founded RNARx and served as its CEO from 2006 to 2013. From 2013 to 2022, she was associated with BioNTech RNA Pharmaceuticals, first as vice president and later senior vice president. In 2022, she left BioNTech to devote more time to research. She received an honorary doctorate from the University of Szeged in 2021 and has since become a professor there.
Reader's Guide
Katalin Karikó's significance lies in her foundational contributions to mRNA-based therapeutics, particularly the discovery of nucleoside modifications that suppress the immunogenicity of RNA, co-discovered with Drew Weissman. This breakthrough overcame a major obstacle to the therapeutic use of mRNA, enabling the development of protein replacement technologies and, critically, the COVID-19 vaccines from BioNTech/Pfizer and Moderna. These vaccines formed the basis for the effective fight against SARS-CoV-2 worldwide and contributed significantly to containing the COVID-19 pandemic. Her work was pursued despite active discouragement from the University of Pennsylvania, which underfunded and deprioritized mRNA research and demoted her in 1995. Her persistence, combined with Weissman's funding and collaboration, eventually led to recognition including the Nobel Prize in 2023. The technology she helped develop has been licensed by BioNTech and Moderna, and her legacy is that of a researcher who overcame institutional skepticism and personal hardship to create a platform that saved millions of lives.
Did You Know?
- Karikó grew up in Kisújszállás, Hungary, in a home without running water, a refrigerator, or television.
- She earned third place in Hungary in a biology competition during primary education.
- In 1985, she left Hungary for the United States with her husband and two-year-old daughter, carrying her daughter's teddy bear stuffed with £900 from selling their car and black-market currency exchange.
- Her key finding on nucleoside modifications was rejected by the journals Nature and Science before being accepted by Immunity.
- Karikó was listed as an intelligence asset by the Communist Hungarian secret police from 1978 to 1985, which she says she was blackmailed into out of fear of repercussions on her career or reprisals against her father.
Frequently Asked Questions
Who is Katalin Karikó?
Katalin Karikó is a Hungarian-American biochemist born in 1955 who became world-renowned for her research into how messenger RNA can be used to instruct cells to produce specific proteins. Her foundational discoveries in the 1990s and 2000s made modern mRNA-based vaccines possible.
What is Katalin Karikó's key scientific breakthrough?
Her landmark contribution was identifying that adding specific chemical modifications to nucleosides in synthetic mRNA could prevent the human immune system from attacking the injected molecule. This solved one of the biggest barriers to using RNA as a therapeutic tool and opened the door to protein replacement strategies.
Why did Katalin Karikó receive the 2023 Nobel Prize in Physiology or Medicine?
She and Drew Weissman were honored for their discovery of nucleoside modifications that allow mRNA to function safely inside human cells without triggering a dangerous immune response. The Nobel committee recognized that this insight became the essential scientific foundation behind the rapid development of mRNA vaccines during the pandemic.
How did Katalin Karikó's research connect to the COVID-19 vaccines?
The mRNA vaccines that protected millions of people during the pandemic relied on the very principle Karikó spent decades proving: that chemically tweaked messenger RNA can be delivered into cells to produce protective proteins without the body rejecting it. Without her early work on immunogenicity suppression, those vaccines would not have been feasible.
What obstacles did Katalin Karikó face before her recognition?
For years she struggled to secure stable academic positions and faced widespread skepticism from the research community, which largely dismissed RNA as a viable therapeutic platform. She persisted through rejections and limited funding until the field finally caught up with the vision she had articulated in the 1990s.
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