And he started with a similar but different observation, and that was that cows get a disease that's very similar to smallpox.
他首先观察到一种类似但不同的情况,就是牛得了一种很像天花的病
So if you got infected with smallpox, you got the disease.
如果你感染了天花病毒,就会得这种病
But variola, which causes smallpox in humans, and vaccinia, which causes a disease called cowpox in cattle, turned out to be, we now know, viruses that are molecularly very similar.
但是导致天花的人痘病毒,和导致牛痘,的牛痘病毒,后来发现其实是,我们现在知道,这两种病毒在分子水平上十分相似
Smallpox affected world history hundreds of years ago, and it was a disease that was common in Europe, but not common in the Americas until the Americas were colonized.
天花影响了几个世纪前的历史,这种病在欧洲很常见,但在美国不多见,直到美国成为殖民地
If I happen to have some other infectious disease, then not only would you passing the protection to smallpox, but you'd be passing that disease among the population as well.
如果正好还有其他传染病,那不仅会传播对天花的免疫能力,也在人群中传播其它传染病
If smallpox occurred in your community, about 30 percent of the people that acquire the disease would die from it; the other 70 percent could be disabled or permanently disfigured as a result of the disease.
如果你周围有人得了天花的话,那么百分之三十的天花病人,会因此死亡,剩下的百分之七十会成为残疾或永久毁容,这都是天花造成的
And he hypothesized that they were getting the disease in cows, which the disease from cows that caused a milder disease than smallpox, and that protected them from getting the more severe forms of smallpox later.
他假定奶牛将这种疾病传染给挤奶女工,这种源自奶牛的疾病比天花更温和,它保护女工们,免受更为严重的天花感染
And that was possible in smallpox because of a few characteristics of the disease: one is that it's a--it's purely a human disease, humans are the only organisms that are affected by it.
天花能够被根治的原因在于,这种疾病具有以下几个特点,一是,它是一种只有人类才得的疾病,人类是唯一受天花感染的生物
应用推荐