Nobel Prize for medicine goes to developers of mRNA vaccines

Katalin Karikó and Drew Weissman receive a dose of the COVID-19 vaccine. Their 2005 therapeutic technology discovery with mRNA laid the groundwork for the vaccine.

_{© Penn Medicine}

The Nobel Prize for physiology or medicine will go to two scientists who pioneered research of messenger RNA (mRNA) for human vaccines, paving the way for COVID-19 vaccines in the pandemic.

Katalin Karikó, PhD, and Drew Weissman, MD, PhD, were honored by the Nobel Assembly at the Karolinska Institutet, which announced the prize Oct. 2. Kariko’ and Weissman were colleagues at the University of Pennsylvania, where their collaboration focused on how different RNA types interact with the immune system, according to the Nobel Assembly.

“Through their groundbreaking findings, which have fundamentally changed our understanding of how mRNA interacts with our immune system, the laureates contributed to the unprecedented rate of vaccine development during one of the greatest threats to human health in modern times,” the Karolinska Institutet’s news release said.

“The impressive flexibility and speed with which mRNA vaccines can be developed pave the way for using the new platform also for vaccines against other infectious diseases,” the news release said. “In the future, the technology may also be used to deliver therapeutic proteins and treat some cancer types.”

Strong medicine

Katalin Karikó, PhD
_{The Karolinska Institutet}

Drew Weissman, MD, PhD

_{The Karolinska Institutet}

Vaccines stimulate the formation of an immune response to a particular pathogen, giving the body a head start in fighting disease if there is a later exposure, the Nobel Assembly said in its explanation about Karikó and Weissman’s research.

Vaccines based on killed or weakened viruses, such as those against polio, measles and yellow fever, have been in use for decades. The 1951 Nobel Prize in Physiology or Medicine went to Max Theiler for developing a vaccine against yellow fever.

In more recent times, scientists have developed vaccines based on individual viral components, such as proteins and vectors, or parts of the viral genetic transferred to harmless carrier viruses.

For all those, producing vaccines requires large-scale cell culture, which takes time and resources, according to the Nobel Assembly.

In the 1980s, scientists found efficient methods to produce mRNA without culturing cells, called in vitro transcription. But the method “was considered unstable and challenging to deliver,” requiring sophisticated carrier lipid systems and causing inflammatory reactions, according to the Nobel Assembly.

‘The breakthrough’

Karikó and Weissman found different variants of mRNA caused different reactions in cells – including almost abolishing inflammatory response.

“This was a paradigm change in our understanding of how cells recognize and respond to different forms of mRNA,” the Nobel Assembly summary said. “Karikó and Weissman immediately understood that their discovery had profound significance for using mRNA as therapy.”

They published their results in 2005 and continued their study and by 2010, several companies were working on mRNA technology, pursuing vaccines against Zika virus and MERS-CoV. When COVID-19 emerged, the stage was set to develop two mRNA vaccines “at record speed,” with 95% effectiveness and approval by December 2020.

“The vaccines have saved millions of lives and prevented severe disease in many more, allowing societies to open and return to normal conditions,” said the Nobel Assembly. “Through their fundamental discoveries of the importance of base modifications in mRNA, this year's Nobel laureates critically contributed to this transformative development during one of the biggest health crises of our time.”

Meet the honorees

The Nobel Assembly published biographies of the recipients.

Born in Hungary, Karikó received her doctorate from Szeged’s University and performed postdoctoral work there until 1985. She conducted additional postdoctoral research at Temple University and the University of Health Science. In 1989, she was appointed assistant professor at the University of Pennsylvania, where she remained until 2013.

Karikó is senior vice president at BioNTech RNA Pharmaceuticals, with professorship at Szeged University and adjunct professorship at the Perelman School of Medicine at the University of Pennsylvania.

Born in Lexington, Massachusetts, Weissman earned his medical doctor and doctorate degrees from Boston University. He did his clinical training at Beth Israel Deaconess Medical Center at Harvard Medical School and postdoctoral work at the National Institutes of Health.

In 1997, he established his research group at the Perelman School of Medicine at the University of Pennsylvania, where he remains the Roberts Family Professor in Vaccine Research and director of the Penn Institute for RNA Innovations.