MicrobeWorld

Louis Pasteur develops a method of attenuating a virulent pathogen the agent of chicken cholera, so it would immunize and not cause disease. This is the conceptual breakthrough for establishing protection against disease by the inoculation of a weakened strain of the causative agent. Pasteur uses the word ”attenuated” to mean weakened. As Pasteur acknowledged, the concept came from Edward Jenner’s earlier success at smallpox vaccination.

More Information:

Plasmids, Pasteur, and Anthrax, ASM News 49,1983. p.320 [pdf]

Pasteur, L. 1880. De l'attenuation du virus cholera des poules. Compte rend. Acad. se. 91: 673-680 In Milestones in Microbiology: 1556 to 1940, translated and edited by Thomas D. Brock, ASM Press. 1998, p126 [pdf]