There’s another reason to take heart. Although a particular virus could be virulent against humans, it’s not likely to kill all of us. Genetic variations between members of the human species mean that there will always be some people who don’t succumb to a particular infection. This has already been demonstrated recently with HIV—and needless to say is a subject of much research since it may yield clues for the fighting of the virus for everyone else. （选自《英语沙龙》，2003年第8期）
此外，还有一个令人振奋的原因。虽然某种特定的病毒可能对人是致命的，但是它不可能毁灭整个人类。人群中的基因变异意味着总有一些人不会被某种特定的感染整垮。这一点最近已经通过艾滋病病毒得到证实。不用说，这是一个热门的研究课题，因为它可能为人类与病毒的抗争提供有用的线索。（许歆 选译，有改动）
