Fukuda notes a pandemic has nothing to do with the severity of the disease, but rather with its geographic spread.

VOA: standard.2009.05.14

As we'll see in section today, a vaccine does not have to be totally perfect in order to prevent transmission of a disease, because when a disease enters a community its spread from one person to another.

有如我们今天看到的,疫苗不一定非要,绝对完美地阻止疾病的传播,因为当疾病侵入一个社区后,会在人群间传播

耶鲁公开课 - 生物医学工程探索课程节选

Some scientists have said the government should cancel large sporting events and close schools to try to stop the spread of the respiratory disease.

VOA: standard.2009.05.30

But the prime minister also admits that in a country where HIV and AIDS victims are often abandoned by their families, fear of the disease could make it almost impossible to stop its spread.

VOA: standard.2009.04.04

"It just is not a good idea." Swine flu parties are the latest version of chickenpox parties, where parents encourage their kids to share lollipops, spoons or whistles to spread the disease and get immunity.

VOA: standard.2009.12.18

Scientists warn that without an agreement to reduce so-called green house gas emissions, global temperatures will continue to rise, with the catastrophic consequences of extreme weather events, the spread of drought and disease, and the extinction of plant and animal species.

VOA: standard.2009.12.09