How was Emil Adolf von Behring awarded the Nobel Prize in Physiology or Medicine?

Name: Emil Adolf von Behring.
Country: Germany.
Date of Birth: 15 March 1854.
Died: 31 March 1917.
Education: Doctoral Degree in Medicine Friedrich-Wilhelms-Institut, the Prussian army’s medical college, in Berlin.
Subjects Of Study: Antitoxin Diphtheria Antitoxin.
Known as: Diphtheria antitoxin/serum.
Noble Prize Year: Nobel Prize for Peace in 1901, for his work on serum therapy, particularly for its use in the treatment of diphtheria.