Jules Bordet made a number of pioneering discoveries in immunology. He was the author of Traité de l'Immunité dans les Maladies Infectieuses (Treatise on Immunity in Infectious Diseases; 2nd ed., 1939) and numerous other medical publications.

Born in Soignies, Belgium, the second son of a schoolteacher, Bordet received his medical degree from the University of Brussels in 1892. In 1894, a Belgian government scholarship enabled Bordet to work in Elie Metchnikoff's laboratory at the Pasteur Institute in Paris, where he remained until 1901. In 1899, Bordet married Marthe Levoz; they had two daughters and a son.

At Metchnikoff's laboratory, Bordet investigated bacteriolysis, the phenomenon of cholera bacteria dying when injected into immunized animals (discovered in 1894 by Pfeiffer and Issaeff). Bordet found that serum contains two substances: a preventive substance (a specific antibody) and a bactericidal substance. When he heated serum to 55°C, the antibodies remained, but the bactericidal substance vanished...