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
History of smallpox in Mexico caused Viceroy Félix Calleja to take preventive measures like fumigations and vaccination, which were successful. There were sporadic outbreaks until 1826 when smallpox appeared in Yucatán, Tabasco and Veracruz brought by North American ships. In 1828, there were reported cases in Hidalgo, Oaxaca, State of Mexico, Guerrero, Chiapas, Chihuahua and Mexico City. Efforts to eradicate smallpox in Mexico started with Dr José Ignacio Bartolache who wrote a book in 1779 about smallpox called “Instrucción que puede servir para que se cure a los enfermos de las viruelas epidemicas que ahora se padecen en México”(Instructions that may help to cure smallpox