This was the first person to try to prevent smallpox.
More than a thousand years ago, there are records of Chinese medicine men carrying out a practice known as variolation (named after smallpox, or variola, virus). This involved taking the dried scabs from smallpox victims, grinding them to a powder and blowing them up the victim's ... err, sorry ... patient's nose.
Did it work ?
Yes ... and no. Smallpox strains can be divided into variola major (bad news, 25-30% death rate) and variola minor (same symptoms but 1% or lower death rate). Talented medical men probably tried to select variola minor patients to prepare the material for inoculation. Cut price doctors, however ...