Jenner was inspired by the milkmaid's comments to devise a much better solution: a harmless but effective injection to confer immunity. He hypothesised that if he gave mild cowpox to people, it would stimulate some sort of internal safety system to protect people against smallpox. In an era of blood-letting leeches and purgatives of mercury, this was a revolutionary concept. No-one then knew about immune systems. In many ways, Jenner was centuries ahead of his time.
Copyright ©2024
