white cow: Luna have you noticed that the milkmaid that milk us haven't caught that horrible disease called smallpox? brown cow: oh yeah, I have noticed, I wonder why that is...
Lady in a blue dress: Oh no! I have smallpox! why is that? I have only gone out to town but I have not been to any unclean places! Lady in Brown Dress: Hmm.. I don't have them and I have been in the fields with cows all day.
Lady in brown dress: Mr. Jenner, Lady Marry is very sick and it looks like she has smallpox. I am very confused and I don't know how she caught them and I did not. Edward Jenner: Hmm you said you were in the field all day milking the cows, and where was lady marry? Oh and are your cows sick by any chance?
white Cow: You know that the milkmaid that treats us has contracted cow pox? Brown cow: Yeah, and probably because of that she has not contracted small pox?
Jenner took fluid from a cowpox blister and scratched it into the skin of James Phipps, an eight-year-old boy. A single blister rose up on the spot, but James soon recovered. On July 1, Jenner inoculated the boy again, this time with smallpox matter, and no disease developed. The vaccine was a success. Doctors all over Europe soon adopted Jenner’s innovative technique, leading to a drastic decline in new sufferers of the devastating disease.
And that's how Edward Jenner discovered vaccination and saved many people!