The 2011 Nobel Prize for Medicine has been awarded to three scientists for their work increasing understanding of the immune system.

The award, announced Monday in Stockholm , went to Bruce Beutler of the United States, Jules Hoffmann of Luxembourg and Ralph Steinman of Canada. Beutler and Hoffmann will split half the nearly $1.5 million prize money, while Steinman receives the other half.

They have been credited with work that could lead to new prospects for curing cancer and other diseases.

The Royal Swedish Academy of Sciences will name the winner in physics Tuesday and chemistry Wednesday. An award for economics, given in memory of Alfred Nobel, will be announced October 10.

The 2011 Nobel Peace Prize recipient will be named Friday.

The Nobel Prizes were created by Alfred Nobel, a wealthy Swedish industrialist who invented dynamite. The first Nobel Prizes were awarded in 1901.

Ninety-one Nobel Peace Prizes have been awarded. On 19 different occasions, the prize committee felt there were no nominees who met the criteria for the award..

The International Committee of the Red Cross has been recognized most often, with three awards.

Only one Peace laureate has declined the award. In 1973 Vietnamese politician Le Duc Tho, was recognized along with U.S. Secretary of State Henry Kissinger. Le Duc Tho declined the Nobel Peace Prize.