Viruses are strange things. Though there is some scientific question about whether viruses are alive or not, they do have a basic genetic structure that allows them to be biologically active. But they don't have the built-in reproductive capacity of bacteria -- tiny, living organisms which, once they have infected a human host, can make copies of themselves using their own DNA.
John Connor, a virologist at Boston University in Massachusetts, explains that in order for viruses to reproduce and become a disease threat, they must first hijack the genetic machinery of a living cell:
“They’re parasites," said Connor. "They get inside our cells and use a lot of our machinery in order to make extra copies of themselves. And so that poses a really delicate question of how do you destroy the virus without getting yourself.”
Connor and his colleagues screened thousands of chemical compounds, looking for ones that showed strong antiviral activity.
They identified several small molecules that interfere with the replication of a class of pathogens known as NNS viruses, which cause the deadly Marburg and Ebola infections, as well as measles and mumps.
1.pathogen n. 病原体；病菌
Compost is not necessarily pathogen-free.
2.reproductive adj. 生殖的；再生的；复制的
Every animal has reproductive organs.
The lazy man was a parasite on his family.
4.antiviral adj. 抗病毒的；抗滤过性病原体的
Interferon is probably the most significant nonspecific antiviral substance.
5.measles n. [内科] 麻疹；风疹
Measles ails the little girl.
Mumps is a children's disease.