The Nobel Prize in Physiology or Medicine has been awarded to three scientists for their discovery of hepatitis C—a breakthrough that has saved millions of lives. Americans Harvey Alter and Charles Rice and British scientist Michael Houghton were named as the winners Monday morning by Thomas Perlmann, the head of the Nobel Committee. Prior to their work, hepatitis A and B had already been discovered, but most blood-borne hepatitis cases remained unexplained. The committee explained: “The discovery of hepatitis C virus revealed the cause of the remaining cases of chronic hepatitis and made possible blood tests and new medicines that have saved millions of lives.” The award is the first of six Nobel Prizes being announced through Oct. 12—the remaining prizes are for physics, chemistry, literature, peace, and economics.