Smallpox and a rural observation
Smallpox killed many people in the eighteenth century and often left survivors scarred. Variolation was already used for prevention but involved exposure to smallpox material. Edward Jenner, a physician in rural England, examined reports that some milk workers who had experienced cowpox did not subsequently develop smallpox. He connected these observations with individual cases, investigating the disease and the protection it might provide.
The inoculation on 14 May 1796
On 14 May 1796, Jenner took material from a cowpox lesion on the hand of the dairy worker Sarah Nelmes and inoculated James Phipps, a boy of about eight. Phipps developed a local lesion and a brief illness. Jenner recorded the progression of the symptoms. The episode became Case XVII in his investigation published in 1798, giving a dated account of the inoculation and its aftermath.
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Further inoculation and publication
On 1 July, Jenner inoculated Phipps with smallpox material and reported that smallpox did not follow. His 1798 book brought together several cases, describing inoculation materials, lesions and outcomes in a medical report that others could examine. As physicians repeated vaccination elsewhere, keeping material usable, recognizing suitable lesions and comparing results became practical questions in extending the method.
Vaccination became a shared practice
Jenner continued to collect experience and published an account of the origins of vaccination in 1801. Correspondence, exchanges of material and case reports helped physicians adopt the procedure. Vaccination entered the work of hospitals, armed forces and local public health, followed by improvements in production and administration. The experiment of 1796 became part of a continuing practice requiring observation of protection, reliable supplies and organized delivery.