VOA常速英语2017--HIV或越“变”越弱

HIV, the virus that causes AIDS, frequently mutates. That has allowed the virus to bypass the immune system and infect about 80 million people over the last 35 years. However, researchers say the rapid evolution of HIV actually may be reducing its ability to cause AIDS.

人类免疫缺陷病毒(Human Immunodeficiency Virus)是引发艾滋病的病毒，这种病毒变异频繁。这种特点就让它可以无视免疫系统，并在过去的35年中感染了近8千万人。不过，研究人员表示，该病毒的快速演变实际上可能会降低其引发艾滋病的能力。

Oxford¹ University Professor Phillip Goulder, the lead scientist in the study, said, “One of the quintessential features of HIV is its ability to mutate and evade² the best things we can throw at it, whether its immune responses or antiretroviral drugs. That’s its real strength.”

哈佛大学的菲利普教授是牵头该项研究的科学家，他说，“HIV的一个核心特征是它的变异能力和躲避能力，它能躲避开任何东西，包括免疫应答或抗逆转录药物。这是它的强大之处。”

But HIV is not omnipotent³.

但HIV病毒也不是万能的。

“Even HIV has some weaknesses. The fact is there are some parts of the virus that really don’t like to change. And one of these regions is the central core that encapsulates the two copies of the viral RNA and the various viral enzymes⁴. That region of the virus can mutate. But if it mutates it usually damages the ability of the virus to multiply, replicate⁵, efficiently⁶.”

“即便HIV也有自己的弱点。其实，这种病毒的某些部分厌恶改变。其中一处就是含有2个病毒性核糖核酸(RNA)复制体和多种病毒酶的核心部分。病毒的这一部分可以进行变异。但这个地方变异了，通常会破坏HIV有效繁殖和复制的能力。”

RNA is a molecule⁷ necessary in the production of proteins that are essential for life.

核糖核酸(RNA)是合成生命必须蛋白质的必要分子。

Goulder said the most effective responses to HIV target the capsid protein. It encloses the virus’ nucleic acid, which allows the transfer of genetic⁸ information between different generations of the virus.

菲利普教授说，对HIV病毒最有效的应答是攻击其衣壳蛋白质。衣壳蛋白质上有HIV的核酸，核酸是HIV传递遗传信息的关键。

HIV’s many mutations take their tol.

太多的变异反而降低了HIV的毒性。

“The accumulation of these mutations over time effectively results in a diminution⁹ of the ability of the virus to infect cells efficiently and to cause disease. So that’s a good thing.”

“经年累月的变异不断积累，最终降低了HIV有效感染细胞和引发疾病的能力。所以这是一件好事。”

HIV, he said, becomes less virulent¹⁰, losing some ability to cause AIDS through the collapse¹¹ of the immune system. But could HIV ever reach the point where it mutates into something that does not cause disease?

HIV病毒，他说，它的病毒性愈发降低，逐渐失去了其通过破坏免疫系统来引发艾滋病的能力。但HIV是否能变异到不再引发疾病的程度呢？

“It is but speculative¹² to say what’s going to happen in 10 years of tens of decades. If the trend that we’ve seen in the last 10 years in Botswana were to continue – and I see no reason why it shouldn’t – I think the number of people who can control the virus through their immune system would definitely go up – or be expected to go up – and eventually could be some tens of decades down the track – the majority of people.”

“可以预测未来十年甚至几十年内将会发生什么。如果过去10年中我们在博茨瓦纳(非洲中南部国家)的所见能延续——我确实认为没有理由无法继续——那么我认为能通过自身免疫系统来控制HIV病毒的人数一定会上涨——或很有希望上涨——也可能最终要用上百年的时间——大多数人能做到。”

The research was based on the HIV-1 strain that typically infects people in southern Africa. Goulder pointed¹³ out that another strain of the virus, HIV-2, which occurs in West Africa, causes AIDS in a smaller fraction of people it infects.

该研究是以在南非感染无数人的HIV-1型流行株为研究对象的。菲利普指出，而感染HIV-2型流行株继而引发艾滋病的西非人数量要比前者少。

“You know, it’s not impossible to see HIV becoming less of a cause of disease. And that’s what you see in the monkeys who are naturally infected with SIV, the relation of HIV, which is where we actually got HIV from. They suffer no disease at all.”

“大家都知道，要让HIV不再引发艾滋病也不是不可能的。这一点我们在自然感染猿猴免疫缺损病毒(SIV, Simian¹⁴ Immunodeficiency Virus)的猴类身上已经得到了证实，而人类就是从猴类身上感染了SIV的相关病毒HIV的。如今猴类已不再受SIV的侵扰了。”

SIV stands for Simian Immunodeficiency Virus.

SIV是Simian Immunodeficiency Virus的缩写。

Professor Goulder also said the greater use of antiretroviral drugs appears to affect the virulence¹⁵ of HIV. The drugs may accelerate the evolution of those HIV variations that have a “weaker ability to replicate.”

菲利普教授还说，加大抗逆转录药物的使用似乎影响了HIV的毒性。这种药物可能让HIV加速演化为变种，而变种“繁殖的能力更弱。”

The findings appear in the journal Proceedings¹⁶ of the National Academy of Sciences. Goulder and his Oxford colleagues worked with scientists from South Africa, Canada and Japan, as well as Harvard University and Microsoft Research.

上述发现已发表在《美国国家科学院院刊》上。这是菲利普教授及其哈佛同事与来自南非、加拿大、日本以及哈佛大学和微软研究院的科学家一道合作的结果。

1 Oxford   

n.牛津（英国城市）

参考例句：

• At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
• This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。

2 evade   

vt.逃避，回避；避开，躲避

参考例句：

• He tried to evade the embarrassing question.他企图回避这令人难堪的问题。
• You are in charge of the job.How could you evade the issue?你是负责人，你怎么能对这个问题不置可否？

3 omnipotent   

adj.全能的，万能的

参考例句：

• When we are omnipotent we shall have no more need of science.我们达到万能以后就不需要科学了。
• Money is not omnipotent,but we can't survive without money.金钱不是万能的，但是没有金钱我们却无法生存。

4 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

5 replicate   

v.折叠，复制，模写；n.同样的样品；adj.转折的

参考例句：

• The DNA of chromatin must replicate before cell division.染色质DNA在细胞分裂之前必须复制。
• It is also easy to replicate,as the next subsection explains.就像下一个小节详细说明的那样，它还可以被轻易的复制。

6 efficiently   

adv.高效率地，有能力地

参考例句：

• The worker oils the machine to operate it more efficiently.工人给机器上油以使机器运转更有效。
• Local authorities have to learn to allocate resources efficiently.地方政府必须学会有效地分配资源。

7 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

8 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

9 diminution   

n.减少；变小

参考例句：

• They hope for a small diminution in taxes.他们希望捐税能稍有减少。
• He experienced no diminution of his physical strength.他并未感觉体力衰落。

10 virulent   

adj.有毒的，有恶意的，充满敌意的

参考例句：

• She is very virulent about her former employer.她对她过去的老板恨之入骨。
• I stood up for her despite the virulent criticism.尽管她遭到恶毒的批评，我还是维护她。

11 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

12 speculative   

adj.思索性的，暝想性的，推理的

参考例句：

• Much of our information is speculative.我们的许多信息是带推测性的。
• The report is highly speculative and should be ignored.那个报道推测的成分很大，不应理会。

13 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

14 simian   

adj.似猿猴的；n.类人猿，猴

参考例句：

• Ada had a wrinkled,simian face.埃达有一张布满皱纹、长得像猿猴的脸。
• Curiosity is the taproot of an intellectual life,the most valuable of our simian traits.好奇是高智生命的根源，也是我们类人猿特征中最有价值的部分。

15 virulence   

n.毒力，毒性；病毒性；致病力

参考例句：

• The virulence of the café owner's anger had appalled her.咖啡店老板怒气冲天，充满敌意，把她吓坏了。
• Medical authorities were baffled,both as to its causes and its virulence.医疗当局对其病因及有多致命都还不甚了解。

16 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼