Scientists Receive Nobel Prize for Development That Led to COVID-19 Vaccines

Katalin Kariko and Dr. Drew Weissman, both of the University of Pennsylvania, were awarded the prize.
Scientists Receive Nobel Prize for Development That Led to COVID-19 Vaccines
Nobel Committee member Thomas Perlmann speaks to reporters in front of a picture of this year's laureates Katalin Kariko and Dr. Drew Weissman during the announcement of the winners of the 2023 Nobel Prize in Medicine at the Karolinska Institute in Stockholm, Sweden, on Oct. 2, 2023. (Jonathan Nackstrand/AFP via Getty Images)
Zachary Stieber

Two scientists who executed a development that helped lead to the Pfizer and Moderna COVID-19 vaccines received a Nobel Prize on Oct. 2.

Katalin Kariko and Dr. Drew Weissman jointly received the Nobel Prize in medicine for developing a way to tamp down the body's inflammatory response to messenger ribonucleic acid (mRNA), which was later used in the Pfizer-BioNTech and Moderna COVID-19 shots.

"The discoveries by the two Nobel Laureates were critical for developing effective mRNA vaccines against COVID-19 during the pandemic that began in early 2020," the Nobel Assembly at Karolinska Institutet, which awards the prize in physiology or medicine, said in a statement.

"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."

Dr. Weissman told Reuters after being awarded the prize: "It's an incredible honor. We couldn't have come to the result without both of us being involved."

The prize was awarded for the scientists' work on mRNA in laboratory testing. They discovered that chemically altered nucleoside bases almost entirely removed inflammatory responses.

The research was described in a 2005 paper published by Immunity.

Ms. Kariko, a Hungarian national, and Dr. Weissman, an American, at the time, and at present, are professors at the University of Pennsylvania.

Ms. Kariko went on to a top post at BioNTech, a German biotechnology firm that partnered with Pfizer to make one of the most used COVID-19 vaccines in the world. Pfizer, BioNTech, and Moderna are embroiled in multiple court cases over the mRNA and associated technologies.

BioNTech said on Oct. 2 that the nucleoside base modifications "were one of the key innovations applied to our mRNA-based COVID-19 vaccine" and that the prize was "a reminder for scientists around the world to continue to develop and unlock the full potential of new drug classes."

 (L–R) Katalin Kariko, Ashton Kutcher, Mila Kunis, and Dr. Drew Weissman attend a ceremony in Los Angeles on April 15, 2023. (Araya Doheny/Getty Images for Breakthrough Prize)
(L–R) Katalin Kariko, Ashton Kutcher, Mila Kunis, and Dr. Drew Weissman attend a ceremony in Los Angeles on April 15, 2023. (Araya Doheny/Getty Images for Breakthrough Prize)

Other Scientists Weigh In

Some experts said the scientists deserved the award.

"They demonstrated that changing the type of the RNA nucleotides within the vaccine altered the way in which cells see it. This increased the amount of vaccine protein made following the injection of the RNA, effectively increasing the efficiency of the vaccination: more response for less RNA," John Tregoning, professor of vaccine immunology at Imperial College London, said in a statement.

Others questioned the award going to the scientists.

"Kariko and Weissman get the Nobel, not for inventing mRNA vaccines (because I did that) but for adding the psuedouridine that allowed unlimited spike toxins to be manufactured in what could have been a safe and effective vaccine platform, if safely developed. Good to know," Dr. Robert Malone, an American scientist, wrote on X.

The Karolinska Institutet, based in Sweden, has received funding from Pfizer.

The institute directed a request for comment to the Nobel Assembly at Karolinska Institutet. The committee said it isn't part of the institute and is fully funded by the Nobel Foundation.

Committee members during a briefing downplayed the side effects of the vaccines.

"The adverse effect that's been noted is mostly a mild myocarditis, perimyocarditis, mainly affecting young males. But that normally resolves without any long-term effects," Olle Kampe, one of the members, told reporters. A number of myocarditis cases haven't been mild or transient.

He also said the vaccines are "very efficient and very safe."

According to the University of Pennsylvania, both the Pfizer-BioNTech and Moderna vaccines use licensed technology from the university.

"As a result of these licensing relationships, Penn, Karikó, and Weissman have received and may continue to receive significant financial benefits in the future based on the sale of these products," the university said.


Dr. Malone was the first to discover that human cells could absorb mRNA and produce proteins from it. He also showed for the first time that fatty droplets could be used to ease the mRNA's passage into a living organism.

Those tests were run in 1987. Subsequent testing focused on problems such as stabilizing the mRNA and delivering it effectively.

No mRNA-based vaccines were cleared or distributed until the COVID-19 pandemic struck. The Pfizer-BioNTech and Moderna shots were developed in under one year.

The vaccines use mRNA with chemical modifications, including the replacement of uridine nucleotide with pseudouridine.

Dr. Malone has said those modifications negatively altered the stability of the RNA and have led to the findings of mRNA or spike protein in various parts of vaccinated people weeks or even months after they were vaccinated.

Some others maintain that the modifications are working and will assist with the development of more vaccines and drugs in the future.

"The seminal work of Katalin Karikó and Drew Weissman in understanding of how to configure RNA to be effectively expressed was critical to the success of the highly effective mRNA vaccine against COVID-19," Robin Shattock, professor of mucosal infection and immunity at Imperial College London, said in a statement. "Their fundamental work in using modified nucleotides, the building blocks of RNA, to avoid activation of the innate immune system will be key to the successful use of future RNA vaccines and new RNA-based medicines.”

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