Americans Harvey J. Alter and Charles M. Rice and British-born scientist Michael Houghton won the Nobel Prize for medicine on Monday for their discovery of the hepatitis C virus, a major source of liver disease that affects millions worldwide.

Announcing the prize in Stockholm, the Nobel Committee noted that the trio’s work identified a major source of blood-borne hepatitis that couldn’t be explained by the previously discovered hepatitis A and B viruses. Their work, dating back to the 1970s and 1980s, has helped saved millions of lives, the committee said.

“Thanks to their discovery, highly sensitive blood tests for the virus are now available and these have essentially eliminated post-transfusion hepatitis in many parts of the world, greatly improving global health,” the committee said.

“Their discovery also allowed the rapid development of antiviral drugs directed at hepatitis C,” it added. “For the first time in history, the disease can now be cured, raising hopes of eradicating hepatitis C virus from the world population.”

The World Health Organization estimates there are over 70 million cases of hepatitis C worldwide and 400,000 deaths from it each year. The disease is chronic and a major cause of liver cancer and cirrhosis requiring liver transplants.

The medicine prize carried particular significance this year due to the coronavirus pandemic, which has highlighted the importance that medical research has for societies and economies around the world.

Will Irving, a virologist at the University of Nottingham, said that identifying hepatitis C had been the “holy grail” in medicine.