The Nobel Committee has awarded the 2023 Nobel Prize in Physiology or Medicine to Katalin Karikó and Drew Weissman for their pioneering work in the development of mRNA vaccine technology, which made possible a timely vaccine response to the Covid-19 pandemic. Vaccines based on mRNA technology are widely credited with saving millions of lives and helping to curb the pandemic’s spread.

For decades, scientists from around the world had pursued the idea of using mRNA (messenger RNA) as medicine. The normal role of mRNA in cells is to convey the genetic information written in DNA into a form that can be translated into proteins. Researchers aimed to develop tools to create novel mRNA sequences — ones that code for viral proteins, for example — in the lab, and then introduce those mRNA molecules into cells. The cells would then translate these mRNA sequences into viral proteins, thereby alerting the immune system to mount a defense against the virus. In effect, the mRNA vaccine turn cells into factories for fighting off viral attackers.

However, the first attempts to use mRNA to produce an immune response failed because cells too readily recognized the introduced mRNA molecules as invaders and destroyed them.

In 2005, Karikó and Weissman of the University of Pennsylvania discovered a way to slightly tweak the nucleotide sequence of the mRNA molecules so that they bypassed cellular immune surveillance to produce a protective immune response. The winners’ discovery — a way to induce cells to create an immune response that was both stable and didn’t cause inflammatory reactions — was key to taking mRNA technology and making it applicable to create safe and effective vaccines.

Just 15 years later, their tools were proven on the global stage. Barely a year after the Covid-19 pandemic erupted around the world, multiple pharmaceutical companies had used Karikó and Weissman’s mRNA tools to develop vaccines against the virus, saving innumerable lives.

Their discoveries “fundamentally changed our understanding of how mRNA interacts with our immune system and had a major impact on our society during the recent Covid-19 pandemic,” said Rickard Sandberg, a member of the Nobel Assembly, from the podium this morning at the Karolinska Institute in Sweden.

This article will be updated with additional details throughout the day.

Articles on the Nobel Prizes in Physiology or Medicine from previous years:

2022: Geneticist Awarded Nobel Prize for Studies of Extinct Human Ancestors

2021: Medicine Nobel Prize Goes to Temperature and Touch Discoveries

2020: Scientists Win Nobel Prize for Discovering the Hepatitis C Virus

2019: Nobel Prize Awarded for Discoveries on How Cells Adapt to Oxygen

2018: Nobel Prize Awarded for Cancer Immunotherapy

2017: Nobel Prize Awarded for Biological Clock Discoveries and The Overlooked Link Between Two of This Year’s Nobel Prizes