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
To the Youth in Western Countries To the Youth in Western Countries On 29 November 2015, Ali Khamenei, the Supreme Leader of Iran, published an open letter addressed to the youth in western countries. It is the second letter of its kind, the first one having been published in January 2015. Both were distributed via his accounts on various social media, including Twitter, Facebook and Instagram, using the hashtag #CommonWorry. The second letter deals with Khamenei's views on the causes of recent terrorism. It was written in response to the November 2015 Paris attacks and other contemporary terrorist actions, such as the Metrojet Flight 9268 crash