For example, measles virus is most closely related to the virus causing rinderpest.

例如，麻疹毒引起牛瘟的毒关系最为密。

Vaccination campaigns have driven two viruses essentially to extinction since vaccines were invented in the 1800s: smallpox and rinderpest, which kills cattle.

自 1800 年代发明疫苗以来，疫苗接种运动已使两种毒基本灭绝：天花和牛瘟，它们会杀死牛。

Our intimacy with cattle has been going on for the 9,000 years since we domesticated them—ample time for the rinderpest virus to discover us nearby.

自从我们驯化牛以来，我们牛的亲密关系已经持续了 9000 年，这给牛瘟毒在附近发现我们提供了充足的时间。

The close similarity of the measles virus to the rinderpest virus suggests that the latter transferred from cattle to humans and then evolved into the measles virus by changing its properties to adapt to us.

麻疹毒牛瘟毒的密相似性表明，后者从牛转移到人类，然后通过改变其特性以适应我们而进化为麻疹毒。