Scientists Katalin Kariko and Drew Weissman won the 2023 Nobel Prize in Physiology or Medicine for discoveries enabling the development of COVID-19 vaccines, the award-giving body said on Monday.

The prize, among the most prestigious in the scientific world, is selected by the Nobel Assembly of Sweden’s Karolinska Institute medical university and also comes with 11 million Swedish crowns (about $1 million).

“The 2023 Nobel Prize in Physiology or Medicine has been awarded to Katalin Karikó and Drew Weissman for their discoveries concerning nucleoside base modifications that enabled the development of effective mRNA vaccines against COVID-19,” the body said.

The medicine prize kicks off this year’s awards with the remaining five to be unveiled in the coming days.

The prizes, first handed out in 1901, were created by Swedish dynamite inventor and wealthy businessman Alfred Nobel, and are awarded for achievements in science, literature and peace, and in later years also for economics.