Katalin Kariko and Drew Weissman won the Nobel Medicine Prize on Monday for work on messenger RNA (mRNA) technology that paved the way for groundbreaking Covid-19 vaccines.
The pair, who had been tipped as favourites, "contributed to the unprecedented rate of vaccine development during one of the greatest threats to human health in modern times", the jury said.
The World Health Organization declared Covid a pandemic in March 2020 and the mRNA vaccines were approved for use in December that year. Billions of doses have been injected around the world since then.
Together with other Covid vaccines, they "have saved millions of lives and prevented severe disease in many more", the jury said.
Kariko, 68, and Weissman, 64, longstanding colleagues at the University of Pennsylvania in the United States, have won a slew of awards for their research.
They include the prestigious Lasker Award in 2021, often seen as a precursor to the Nobel.
In honouring the duo this year, the Nobel committee in Stockholm broke with its usual practice of honouring decades-old research, after ensuring it has stood the test of time.
While the prizewinning research dates back to 2005, the first vaccines to use the mRNA technology were those made by Pfizer/BioNTech and Moderna against Covid-19.
Unlike traditional vaccines which use weakened virus or a key piece of the virus' protein, mRNA vaccines provide the genetic molecules that tell cells what proteins to make, which simulates an infection and trains the immune system for when it encounters the real virus.
The pair will receive their Nobel prize, consisting of a diploma, a gold medal and a $1 million cheque, in Stockholm on December 10.
The Nobel will however not be the first gold medal in Kariko's family. Her daughter Susan Francia is a two-time Olympic gold medallist rower.