On one occasion, the village prosecutor asked Qin Na to count the number of people who died of smallpox or acne pits in the village in recent years. He learned from door to door that almost every family had victims of smallpox, but strangely, none of the milkmen in the cattle farm died of smallpox or were pitted.
He asked the milkmaid, have you ever had smallpox? Have cows ever had smallpox? The milkmaid told him that cows will get smallpox, but there are some small pustules on their skin, called vaccinia. The milkman will also get pustules when he vaccinates cows, but it is very mild.
Can you find a safer and more reliable way to prevent smallpox? One day, Qin Na overheard someone say that the milkmaid in the pasture would never get smallpox because she had "vaccinia".
He made an investigation and confirmed this. What is the reason? Jenner went to consult some famous medical experts, but they flew into a rage: "How can things that grow on livestock be inoculated on people?"
It was not until 1874, 78 years after Jenner made the first vaccination experiment, that Germany became the first country in the world to be vaccinated by law.
Extended data:
Who's Jenna? 18? /kloc-a doctor in a small town called Berkeley in England in the 0 th and 9 th centuries. At the time when he lived, a terrible disease called smallpox was prevalent in continental Europe.
It is like the shadow of death, where it appears, it will suffer. Even those who survive by luck will be covered with ugly scars left by smallpox blisters and become ugly and ugly. ?
Qin Na packed up and went to the countryside, squatting in the cowshed year after year to observe the situation of cows getting pox. It turns out that cowpox is a disease that occurs in cows and other livestock. The symptoms are very similar to smallpox. When domestic animals are sick, many blisters filled with pus will also grow on their bodies.
References:
Baidu Encyclopedia-Edward Senna