We have to ask why smallpox was a unique event, and we never used this method for any other virus. Did we even ever consider it?
There are two strains of smallpox, one of which is much less deadly than the other. People practicing variolation tended to use variolous material from a mild cases, including those successfully variolated. Some of the success of smallpox variolation was probably due to this practice and the resulting tendency for the inoculations to contain variola minor.
There are two strains of smallpox, one of which is much less deadly than the other. People practicing variolation tended to use variolous material from a mild cases, including those successfully variolated. Some of the success of smallpox variolation was probably due to this practice and the resulting tendency for the inoculations to contain variola minor.