Two scientists whose "groundbreaking findings" transformed the threat of the pandemic have been awarded the Nobel Prize in medicine. Katalin Kariko and Drew Weissman were recognized on Monday for laying the groundwork for COVID-19 vaccines.

Members of the Nobel panel say the laureates contributed to the unprecedented rate of vaccine development during "one of the greatest threats to human health" in history. "They have saved millions of lives, prevented severe COVID-19, reduced the overall disease burden and enabled societies to open up again," said Rickard Sandberg, a member of the Nobel Assembly at the Karolinska Institute near Stockholm.

Kariko and Weissman enabled the creation of what are known as messenger RNA vaccines. Such molecules carry instructions that help cells defend against infection.

"We never gave up," Weissman said. "We just kept persevering and kept working at it and here we are today."

The pair met over a photocopier at the University of Pennsylvania more than 20 years ago. Weissman said, at first, they could not get any attention or funding. Ten years ago, Kariko was forced to retire from the university.

"We worked hard, but we enjoyed it," Kariko said. "It's not coming easy, but it is fun. And we do it with great happiness."

Kariko and Weissman know the applications of their work can go further. They say they hope, one day, such vaccines may even help protect against cancer and other deadly diseases.