Chen Jingke continued to use his own words to explain the reason: "The elders in my family speculated that genes secrete a special substance."
"When a person eats another person, his genes sense this substance and know that he has eaten the same kind."
"Then prions are produced to kill him to prevent him from eating other people of the same kind, ensuring that the human race can be passed on."
Afraid that Sun Simiao would continue to ask questions, he simply said: "Actually, these are deduced by the elders based on reality, and genes are also hypotheses deduced. I don't know if they are correct or not."
"The reason why this hypothesis is recognized by the elders is because after reasoning based on this hypothesis, it is found that many phenomena can be explained."
Sun Simiao agreed: "In your words, our method of observing the world is still too backward. Many things can only be deduced and hypothesized based on appearances... Should you make bold assumptions and verify them carefully?"
"The production of prions by genes and cannibalism is indeed a very interesting hypothesis, not to mention that experiments have been done on cattle... Are there any other speculations?"
In fact, Chen Jingke did not know that there was a major mistake in his understanding of prions.
However, he himself did not know this. Seeing that Sun Simiao accepted this hypothesis, he breathed a sigh of relief and said, "Yes, they also discovered many interesting things during the research, which can all be explained by genes."
"When a person only eats 70% full at each meal, do not change clothes immediately when the seasons change, but cover up in spring and freeze in autumn... This person's body will be particularly strong and less likely to get sick."
"When a person eats well every meal and changes clothes early when the seasons change...this person's physical condition is average."
"Extend this observation time line to twenty years, fifty years, or even longer."
"It was discovered that the physical fitness of the latter and their descendants is getting worse from generation to generation, and it is becoming more and more difficult to give birth to healthy heirs. In the end, it will even turn into difficulties in having healthy heirs."
"The elders speculate that this is the role of genes. When a person's living conditions are relatively harsh, genes will explode with more potential in order to be passed on..."
"When a group lives in a very favorable environment for hundreds of generations, genes will become 'lazy'..."
"Of course, reasonable living and eating habits and proper exercise are the most important factors. Going hungry every day and having a full meal, and overexerting your physical strength by doing exercise are courting death."
"If this guess is true, the health care plan we have formulated will be more effective with less effort. For example, eating only seven-tenths of the full meal, such as spring cover and autumn jelly... all have a certain reason."
Sun Simiao did not comment, but said: "Is there any more? Let's continue."
Chen Jingke took a breath and said, "One of them is related to asthma."
"The family once built a large number of workshops on an island, which produced too much smoke and caused poor air quality."
"People who breathe this polluted air for a long time will suffer from various diseases, especially respiratory diseases."
"When the elders learned about this situation, they moved some workshops away from human habitation. The air quality has improved and everyone is very happy."
"But no one expected that in the next few years, the chance of asthma infection among people living on the islands would increase several times."
"They searched for various suspicious points but found no problems. In the end, they could only make assumptions based on genes."
"The gene sensed that the local people lived in polluted air and were susceptible to respiratory diseases, so they strengthened their resistance to respiratory diseases."
"When the air quality became better, genes sensed that the danger was gone, and stopped strengthening this aspect, which instead led to concentrated outbreaks of asthma."
Sun Simiao nodded slowly and said: "This is an interesting guess, but it is not enough to prove that genes are at work."
Chen Jingke did not refute, but mentioned another example: "There is also smallpox. As we all know, people who have been infected with smallpox will not be infected a second time."
"In fact, cows can also be infected with smallpox, which is cowpox. Then the elders discovered that some of the milking servants were infected with cowpox, and after they recovered, they were not infected with smallpox."
"After research, they were surprised to find that the toxicity of cowpox is very low. If people are infected with cowpox, they will not develop large areas of acne, let alone kill people."
"So they took the initiative to vaccinate against cowpox, and then discovered that after successful vaccination, they could actually be immune to smallpox."
"Wow." Sun Simiao suddenly stood up from his chair, stared at him closely and said, "Is what you said true?"
Chen Jingke knew why he was so excited and said with certainty: "Of course it is true. Many people in the family have been vaccinated with cowpox, and then took the initiative to come into contact with smallpox patients, and they will not be infected."
Sun Simiao was so excited that he trembled all over and said, "Have you...have you been vaccinated against cowpox?"
Chen Jingke shook his head and said: "No, but I have been vaccinated against tuberculosis. I will be resistant to tuberculosis until I am twenty-four years old."
As he spoke, he rolled up his sleeves, revealing the scars on his left arm, and said, "This is the scar left by the tuberculosis vaccine."
In fact, it is the BCG vaccine. The United Nations announced the elimination of smallpox in 1980, and smallpox vaccination has been discontinued since then.
In China, the smallpox vaccine was changed to the BCG vaccine to prevent tuberculosis.
However, the BCG vaccine is not lifelong effective. Children under four years old are close to 100% immune, and those between four and fifteen years old have a probability of immunity of more than 90%.
The immunity probability is about 65% for those aged 15 to 24, and only 20% for those aged 25 to 35. It is useless no matter how old you are.
Sun Simiao became even more excited and said: "Can you be immune to tuberculosis? How can you do it?"
Chen Jingke shook his head and said: "The tuberculosis vaccine is very complicated. It seems that tuberculosis bacteria are extracted from cattle and cultured."
"It takes more than ten years to make the bovine tuberculosis virus lose its toxicity and then inoculate people. Only an elder knows the cultivation method, and no one knows about it after his death."
Sun Simiao's face was full of disappointment, and he was a little dazed, and said: "Is this so? Then... that's really a pity."
Chen Jingke was afraid that he would not be able to bear the blow, so he quickly said: "But cowpox is relatively simple. Just make a small cut on your arm and apply cowpox liquid on the wound."
"Under normal circumstances, you can completely return to normal in about half a month, and your body will develop resistance to the smallpox virus, and you will be immune to smallpox for life."
Sun Simiao's ability to resist attacks is very strong. Although it is a pity that he missed a new medical skill, it was also a huge surprise to obtain the method of cowpox.
However, he still said cautiously: "Are you sure that the cowpox method is feasible?"
Chen Jingke said with certainty: "It's feasible. I have personally seen many people vaccinated with cowpox. I originally wanted to be vaccinated, but unfortunately there was a major change in my family and I couldn't do it."
"Then I was sent to the Tang Dynasty and met you, Master."
Although Sun Simiao was very willing to believe his disciple's words, he still said out of caution: "The matter is of great importance. I have to test it myself before I can confirm whether it is true or false."