Chapter 3 focuses on Jenner and the discovery of vaccination, specifically his translation of the vague notion that cowpox prevented smallpox into a more precise body of knowledge which could distinguish between varieties of cowpox and be the basis for the development of protocols for its effective use. Given the rarity of cowpox, his use of humanised cowpox (vaccine), propagated on children, was to prove critical to the success and viability of the practice. Publishing his findings in 1798, Jenner had to wait a year for his new mode of prophylaxis to gain acceptance. Initially, London-based physicians – Woodville conducting clinical trials and Pearson distributing vaccine – made much of the running. Jenner, however, reasserted his leadership in the field and made championship of vaccination his principal occupation. After considering reports on Jenner’s discovering of cowpox inoculation and making it available to the world, the British parliament granted him a premium in 1802. The Royal Jennerian Society was established in 1803 to promote and support the practice.