Immunology: From Pasteur to Modern Therapeutics

French immunology built on Pasteur's foundation but quickly exceeded it. Élie Metchnikoff's discovery of phagocytosis at the Pasteur Institute revealed immunity's cellular basis. Watching starfish larvae engulf foreign particles, he realized white blood cells actively defended against invaders. This wasn't just passive resistance but active warfare, revolutionizing understanding of how bodies fight disease.

Charles Richet's discovery of anaphylaxis seemed paradoxical—how could immunity kill? His observation that dogs previously exposed to sea anemone toxin died from doses that barely affected naive animals revealed immunity's dark side. This 1913 Nobel Prize-winning work founded allergy medicine and demonstrated that understanding normal processes required studying when they went wrong.

The BCG vaccine against tuberculosis, developed by Albert Calmette and Camille Guérin at the Pasteur Institute Lille, required 13 years of passages to attenuate bovine tuberculosis bacilli. Their persistence through 230 generations of bacteria created a vaccine still used globally. The methodical approach—gradual attenuation with constant testing—established patterns for developing vaccines against difficult pathogens.

Modern French immunology continues this tradition. Françoise Barré-Sinoussi's 1983 discovery of HIV at the Pasteur Institute came from systematic investigation of a new disease. Her team's rapid identification enabled blood test development, saving millions through screening. The subsequent development of antiretroviral therapies, though international, built on French understanding of retroviral biology.