Pierre Paul Émile Roux FRS was a French physician, bacteriologist and immunologist. Roux was one of the closest collaborators of Louis Pasteur (1822–1895), a co-founder of the Pasteur Institute, and responsible for the institute's production of the anti-diphtheria serum, the first effective therapy for this disease. Additionally, he investigated cholera, chicken-cholera, rabies, and tuberculosis. Roux is regarded as a founder of the field of immunology.

Louis Pasteur was a French chemist, pharmacist, and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation, and pasteurization, the last of which was named after him. His research in chemistry led to remarkable breakthroughs in the understanding of the causes and preventions of diseases, which laid down the foundations of hygiene, public health and much of modern medicine. Pasteur's works are credited with saving millions of lives through the developments of vaccines for rabies and anthrax. He is regarded as one of the founders of modern bacteriology and has been honored as the "father of bacteriology" and the "father of microbiology".