Karikó and Weissman win Nobel Prize in medicine for work that enabled mRNA vaccines against COVID-19

FILE - Japan Prize 2022 laureates Hungarian-American biochemist Katalin Kariko, left, and American physician-scientist Drew Weissman, right, pose with their trophies during the Japan Prize presentation ceremony Wednesday, April 13, 2022, in Tokyo. The Nobel Prize in medicine awarded to Katalin Karikó and Drew Weissman for enabling development of mRNA COVID-19 vaccines, it was announced on Monday, Oct. 2, 2023. (AP Photo/Eugene Hoshiko, Pool, File)


Associated Press

STOCKHOLM (AP) -- Two scientists won the Nobel Prize in medicine on Monday for discoveries that enabled the creation of mRNA vaccines against COVID-19 that were critical in slowing the pandemic -- technology that's also being studied to fight cancer and other diseases.

Hungarian-American Katalin Karikó and American Drew Weissman were cited for contributing "to the unprecedented rate of vaccine development during one of the greatest threats to human health," according to the panel that awarded the prize in Stockholm.

The panel said the pair's "groundbreaking findings ... fundamentally changed our understanding of how mRNA interacts with our immune system."


Traditionally, making vaccines required growing viruses or pieces of viruses and then purifying them before next steps. The messenger RNA approach starts with a snippet of genetic code carrying instructions for making proteins. Pick the right virus protein to target, and the body turns into a mini vaccine factory.

In early experiments with animals, simply injecting lab-grown mRNA triggered a reaction that usually destroyed it. Those early challenges caused many to lose faith in the approach: "Pretty much everybody gave up on it," Weissman said.

But Karikó, a professor at Szeged University in Hungary and an adjunct professor at the University of Pennsylvania, and Weissman, of the University of Pennsylvania, figured out a tiny modification to the building blocks of RNA that made it stealthy enough to slip past immune defenses.

Karikó, 68, is the 13th woman to win the Nobel Prize in medicine. She was a senior vice president at BioNTech, which partnered with Pfizer to make one of the COVID-19 vaccines. Karikó and Weissman, 64, met by chance in the 1990s while photocopying research papers, Karikó told The Associated Press.


Dr. Paul Hunter, a professor of medicine at Britain's University of East Anglia, described the mRNA vaccines made by BioNTech-Pfizer and Moderna Inc. as a "game changer" in shutting down the coronavirus pandemic, crediting the shots with saving millions of lives.

The duo's pivotal mRNA research was combined with two other earlier scientific discoveries to create the COVID-19 vaccines. Researchers in Canada had developed a fatty coating to help mRNA get inside cells to do its work. And studies with prior vaccines at the U.S. National Institutes of Health showed how to stabilize the coronavirus spike protein that the new mRNA shots needed to deliver.

Dr. Bharat Pankhania, an infectious diseases expert at Exeter University, predicted the technology used in the vaccines could be used to refine vaccines for other diseases like Ebola, malaria and dengue, and might also be used to create shots that immunize people against certain types of cancer or auto-immune diseases including lupus.


"The future is just so incredible," Weissman said. "We've been thinking for years about everything that we could do with RNA, and now it's here."

Karikó said her husband was the first to pick up the early morning call, handing it to her to hear the news.

"I was very much surprised," Karikó said. "But I am very happy."

The two have collaborated for decades, with Karikó focusing on the RNA side and Weissman handling the immunology: "We educated each other," she said.

Before COVID-19, mRNA vaccines were already being tested for diseases like Zika, influenza and rabies -- but the pandemic brought more attention to this approach, Karikó said. Now, scientists are trying out mRNA approaches for cancer, allergies and other gene therapies, Weissman said.