Three European scientists shared the 2008 Nobel Prize in medicine Monday for separate discoveries of viruses that cause AIDS and cervical cancer, breakthroughs that helped doctors fight the deadly diseases. French researchers Francoise Barre-Sinoussi and Luc Montagnier were cited for their discovery of human immunodeficiency virus, or HIV; while Germany's Harald zur Hausen was honored for finding human papilloma viruses that cause cervical cancer, the second most common cancer among women. The German medical doctor and scientist received half of the 10 million kronor (US$1.4 million) prize, while the two French researchers shared the other half. “I'm not prepared for this,” zur Hausen, 72, of the German Cancer Research Center in Heidelberg, said. In its citation, the Nobel Assembly said Barre-Sinoussi and Montagnier's discovery was one prerequisite for understanding the biology of AIDS and its treatment with antiviral drugs.