Why did the Qing emperors get this strange disease easily?

Speaking of Princess Pearl, I think everyone is familiar with it! There is such a plot in the play. At that time, Wei Zi and Er Kang had given birth to 1 child. The child is named Dong Er. He is very strange. Everyone likes him. It's a pity that the child got sick halfway. It was smallpox. Today, we know less about this disease. Almost no one will get this disease now, and it can be said that it has basically disappeared. You know, in ancient times, this was a particularly terrible incurable disease. Because it is particularly contagious, it is particularly easy to spread in the air without any special media. Another possibility is that due to the relative backwardness of ancient medical technology, people can be said to be helpless about such a disease. Smallpox is not only easy to spread but also very dangerous. If a person accidentally touches it, the chance of survival is particularly small. Therefore, in ancient times, no matter whether you were a prince with high power or a citizen with low status, no matter who got smallpox, their endings were equally tragic. In ancient Asia, many people died of smallpox every year, and many emperors in the Qing Dynasty also suffered from smallpox. For example, both the emperor shunzhi and Emperor Tongzhi had smallpox, but the only difference was that they both survived. Therefore, no matter what your state, other reasons and bad luck, diseases will come to you. In addition to these two emperors, Emperor Kangxi and Emperor Xianfeng were also favored by the Heaven Emperor who survived smallpox, and it was for this reason that they were elected as the emperors of the Qing Dynasty. It is worth mentioning that although these emperors escaped smallpox, they left a lifelong sequela, that is, they were covered with acne pits. So, if they are not the Ninth Five-Year Plan emperors, they can't even marry their wives! No wonder people nowadays say that appearance is not the most important thing, but power and money are the most important. But this statement is not entirely correct. Generally speaking, there are some reasons why the emperors of the Qing Dynasty were prone to smallpox. First, smallpox was rampant in the Qing dynasty, and even with superb medical skills, there was nothing I could do. No matter who has smallpox, there is generally no hope. The difference is that the prince is the heir, who will be taken seriously after illness, and will generally be written into the history books, while ordinary people are different, and no one cares after illness. Second, he lived in the northeast before entering the customs in Qing Dynasty, and only after Nurhachi unified the whole country did he enter the Central Plains. Originally, they lived in one place all the year round, and suddenly changing places would definitely lead to serious acclimatization, so most princes in the Qing Dynasty would get smallpox. In fact, not only the emperors of the Qing dynasty, but also the Manchu people who lived outside the customs were more likely to get sick after coming to the Central Plains than those who lived in the Central Plains. Not only in the Qing Dynasty, but also in Asia, Europe and even the whole world at that time, the mortality rate of smallpox reached a high level in some places. Fortunately, with the development of human civilization, people have developed vaccines to prevent smallpox. ...