Variolation shortly after variolation began to outweigh the benefits of the procedure. From the 1760s, a number of individuals, including John Fewster, Peter Plett, Benjamin Jesty, and particularly Edward Jenner, were interested in the use of material from cowpox, an animal infection, to protect against smallpox. In 1796, Jenner vaccinated James Phipps, did more vaccinations in 1798, and was the first to publish evidence that cowpox protected against smallpox, was safer than variolation, and that his vaccine could be maintained by arm-to-arm transfer. The use of variolation soon began to decline as the smallpox vaccine became widely used and its benefits
Smallpox the United States and South Africa a much milder form of smallpox, "variola minor", was recognized just before the close of the 19th century. By the mid-20th century "variola minor" occurred along with "variola major", in varying proportions, in many parts of Africa. Patients with "variola minor" experience only a mild systemic illness, are often ambulant throughout the course of the disease, and are therefore able to more easily spread disease. Infection with "v. minor" induces immunity against the more deadly "variola major" form. Thus as "v. minor" spread all over the USA, into Canada, the South American countries and