疫苗的

HIV virus mutates rapidly, which has made it especially difficult for researchers to find an effective treatment or vaccine.

HIV病毒繁殖速度极快，因此科学家很难找到有效的治疗方法或发明任何疫苗。

The tip of the spike mutates continually, which means that flu vaccines must be redefined every year.

这种刺突的尖端不断变异，这意味着流感疫苗必须每年重新修改。

The tip of the spike mutates continually, which means that flu vaccines must be redefined every year.

这种刺突的尖端不断变异，这意味著流感疫苗必须每年重新修改。

The second wave of swine flu may be worse. I do not know. But I do know that, if the virus mutates to a more virulent form, the immunisation may in any case not work.

我不知道流感的第二波会不会更加凶猛，但是我知道如果病毒发生了变种，导致病毒毒性增强的话，那么现在这个疫苗也许是怎么也不管用了。

But it added that it had quarantined the batch used at the school as a precaution.

但是它补充说，作为预防它隔离了曾在学校使用的这批疫苗。

Viruses change,or mutate,so flu vaccines must be reformulated each year to target the most common threats.

由于病毒变异和突变，因此流感疫苗必须每年更新来瞄准最普遍的病毒威胁。

Viruses change, or mutate, so flu vaccines must be reformulated each year to target the most common threats.

由于病毒会突变或变异，因此流感疫苗必须每年重新配方，将目标集中于那些最常见的病毒威胁。

Viruses change, or mutate, so flu vaccines must be reformulated eachyear to target the most common threats.

由于病毒会变异或突变，因而必须每年重新配置流感疫苗用以对付最常见的病毒威胁。

Viruses change, or mutate, so flu vaccines must be reformulated each year to target the most common threats.

由于病毒会转变，或变异，因此每年必须重新接种疫苗以对付最常见的病毒症状

Horses 马 need to be shoed, they need to receive vaccinations and they eat quite a lot.

鞋的需要，他们需要接受疫苗注射，他们吃了不少苦头。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。