The Nobel Assembly awarded three researchers the 2008 Nobel Prize in medicine on Monday in honour of their discovery of the AIDS virus and the viruses that cause cervical cancer.
Francoise Barre-Sinoussi and Luc Montagnier, both of France, were honoured for discovering human immunodeficiency virus, or HIV, in 1983.
Germany's Harald zur Hausen was honoured for his discovery of the human papilloma viruses, which may cause cervical cancer.
"I'm not prepared for this," the 72-year-old zur Hausen told The Associated Press. "We're drinking a little glass of bubbly right now."
The researchers shared the US$1.4 million prize money, with zur Hausen receiving half and the two French scientists splitting the other half.
The assembly said the French scientists' breakthrough "was one prerequisite for the current understanding of the biology of the disease and its antiretroviral treatment," according to a press release.
Their discovery has helped other researchers determine how HIV replicates and has "led to development of methods to diagnose infected patients and to screen blood products, which has limited the spread of the pandemic."
There had been a long-standing dispute between Montagnier and U.S. researcher, Dr. Robert Gallo, about who first identified HIV.
The dispute led to an agreement in 1987 between U.S. President Ronald Reagan and French Prime Minister Jacques Chirac that called for the two researchers to divide royalties after their research led to an AIDS blood test.
But in the 1990s, the U.S. government awarded greater share of the royalties to the Montagnier team. The move gave weight to the French belief that Montagnier isolated the virus one year before Gallo.
Even so, Gallo told The Associated Press that he was disappointed at being excluded from the prize.
A maximum of three people can share a Nobel Prize.
Barre-Sinoussi said she and Montagnier had hoped their discovery would prevent a worldwide AIDS pandemic. While their research has led to testing and treatment breakthroughs, progress in these areas was not made in time to prevent the pandemic that has killed an estimated 25 million people worldwide.
"We naively thought that the discovery of the virus would allow us to quickly learn more about it, to develop diagnostic tests -- which has been done -- and to develop treatments, which has also been done to a large extent and, most of all, develop a vaccine that would prevent the global epidemic," Barre-Sinoussi told The Associated Press.
Zur Hausen's discovery "went against current dogma" when he found that some strains of the HPV virus can cause cancer.
His research has also led to the development of vaccines against the virus, which is the most common sexually transmitted infection. It affects between about 50 and 80 per cent of the world's female population.
The vaccine Gardasil was approved in 2006 to protect females between the ages of nine and 26 against cervical cancer.
The vaccine guards against strains of HPV that can cause cervical cancer, including two strains discovered by zur Hausen.
Persistent infection with the virus accounts for more than five per cent of all cancers worldwide.
The medicine prize is most often awarded for a specific discovery rather than for a body of research.
In 2007, it was awarded to U.S. scientists Mario Capecchi and Oliver Smithies, along with Martin Evans of Great Britain, for their research that led to a common technique for manipulating genes in mice.
The breakthrough has allowed scientists to better study heart disease, diabetes, cancer and cystic fibrosis, among other diseases.
The Nobel Prize, which is awarded in medicine, physics, chemistry, literature and peace, was borne from a clause in scientist Alfred Nobel's will in 1896. The first awards were handed out in 1901.
Nobel is best known as the inventor of dynamite.
In addition to a financial reward, winners receive a diploma and attend ceremonies in Stockholm and Oslo on Dec. 10, to mark the anniversary of Nobel's death.
With files from The Associated Press
