But simply injecting lab-grown mRNA into the body triggered an inflammatory reaction that usually destroyed it. 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 those immune defences. 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. She and Weissman, 64, who is a professor and director of the Penn Institute for RNA Innovations, met by chance in the 1990s while photocopying research papers, according to Penn Today, the university’s news website. Dr. Paul Hunter, a professor of medicine at Britain’s University of East Anglia, described the mRNA vaccines as a “game changer” in helping to shut down the coronavirus pandemic, crediting the shots with saving millions of lives. “If it hadn’t been for the mRNA technology, COVID would have been much worse,” he said.

 

“Vaccines generally were the turning point in slowing down COVID and the mRNA vaccines were just so much better than all the others,” he said, noting that the main vaccine used in the UK, made by AstraZeneca, is barely in use anymore. “We would likely only now be coming out of the depths of COVID without the mRNA vaccines,” Hunter said. Dr. Bharat Pankhania, an infectious diseases expert at Exeter University, said that a major advantage of mRNA technology was that vaccines could be made in extremely large quantities since their main components are made in laboratories. Pankhania predicted that 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 immunise people against certain types of cancer or auto-immune diseases like lupus.