Most healthy people infected with the virus show no signs.

VOA: special.2009.05.26

And so even people that got vaccinated, most of us either have questionable or no protection against the virus at this point.

所以就算那些接种过天花疫苗的人,到那时候也不一定,或者压根无法抵御病毒

耶鲁公开课 - 生物医学工程探索课程节选

And the goal was to eradicate the virus, to get rid of it so that there were no natural sources of the virus on the planet.

其目标是根除病毒,完全除掉病毒,让这个星球上不再有病毒的自然来源

耶鲁公开课 - 生物医学工程探索课程节选

There's no known cure for hepatitis B, although the virus can be kept in check with anti-viral medicines.

VOA: standard.2010.07.26

Now, a virus is not capable of reproducing on its own, so if you got a virus into your body somehow and it didn't enter any of your cells, it would cause no damage because it could not reproduce.

病毒自身并不能繁殖,所以如果你的身体感染了病毒,而病毒没有进入细胞的话,因其不能繁殖所以不会对身体造成伤害

耶鲁公开课 - 生物医学工程探索课程节选

Angus Nicoll of the European Center for Disease Prevention says that at this point no one knows whether the virus will become more or less virulent in the months ahead.

VOA: standard.2009.04.30

Chan notes no one can predict what will happen later in the year when the southern hemisphere enters its influenza season and the virus spreads more rapidly throughout the population.

VOA: standard.2010.01.18

Other infectious disease experts,however, have insisted Australia's is over-reacting to the outbreak of the A-H1N1 virus, insisting that,so far, the disease is no worse than other strains of influenza that kill hundreds of Australians every year during the colder winter months.

VOA: standard.2009.05.30