VOA标准英语2011--SIV Vaccine Holds Promise for AIDS

SIV Vaccine¹ Holds Promise for AIDS

Researchers are excited about a vaccine they have developed that protects rhesus monkeys from infection with a primate² version of the AIDS virus. They hope to use what they've learned to develop an agent that prevents HIV infection in humans.
With more than 2.6 million new HIV infections every year, and almost two million deaths from the sexually transmitted virus, an AIDS vaccine remains³ an urgent, but elusive⁴, goal for AIDS researchers.
Now, scientists at the Oregon Health and Science University's Vaccine and Gene⁵ Therapy Institute, or VGTI, think they may finally be on to something. Louis Picker, the head of VGTI's vaccine program, says researchers have developed an agent that protects rhesus macaque monkeys from simian⁶ immunodeficiency virus, or SIV.
He compares the vaccine to an army on alert, springing into action at the first sign of infection, before the virus has had a chance to gain a foothold in the body.
"It keeps armed troops at the borders that are able to intercept⁷ the incoming HIV or SIV right from the beginning," says Picker. "There's no delay that requires the recruitment of effector cells that other vaccines⁸ require."
Effector cells are immune system cells that are mobilized against bacterial⁹ or viral invaders¹⁰.
Currently, vaccine developers try to prime the body's immune system to recognize and destroy HIV by attaching genetic¹¹ material from the virus to a harmless cold virus. But so far, Picker says, the strategy hasn't worked well because the cold virus doesn't survive very long in the body.
Picker's team of investigators¹² used cytomegalovirus instead. CMV infects most of the world's population, rarely causes disease, and remains alive - but dormant¹³ - indefinitely.
In the monkey experiments, researchers gave the primates¹⁴ a genetically-modified cytomegalovirus SIV vaccine or the CMV vaccine plus a modified cold virus vaccine. A third group of rhesus got a standard SIV cold virus vaccine alone and a fourth group was not vaccinated¹⁵.
Researchers then infected the primates with SIV. While the untreated monkeys and those that got the adenovirus vaccine eventually got sick and developed AIDS, Picker says half of the 24 rhesus macaques that received either the CMV vaccine alone or the CMV plus the cold virus vaccine showed no sign of infection.
"And in fact, when we tried to find the virus after a year or so it was very difficult to find by a variety of techniques," says Picker, "raising the possibility of whether the infection had actually been cleared from these monkeys which would be unprecedented¹⁶ for an SIV vaccine."
Picker's goal now is to formulate¹⁷ a more effective CMV vaccine that is safe enough to begin clinical trials in humans against HIV infection.

1 vaccine   

n.牛痘苗，疫苗；adj.牛痘的，疫苗的

参考例句：

• The polio vaccine has saved millions of lives.脊髓灰质炎疫苗挽救了数以百万计的生命。
• She takes a vaccine against influenza every fall.她每年秋季接种流感疫苗。

2 primate   

n.灵长类（目）动物，首席主教；adj.首要的

参考例句：

• 14 percent of primate species are highly endangered.14%的灵长类物种处于高度濒危状态。
• The woolly spider monkey is the largest primate in the Americas.绒毛蛛猴是美洲最大的灵长类动物。

3 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

4 elusive   

adj.难以表达(捉摸)的；令人困惑的；逃避的

参考例句：

• Try to catch the elusive charm of the original in translation.翻译时设法把握住原文中难以捉摸的风韵。
• Interpol have searched all the corners of the earth for the elusive hijackers.国际刑警组织已在世界各地搜查在逃的飞机劫持者。

5 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

6 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。

7 intercept   

vt.拦截，截住，截击

参考例句：

• His letter was intercepted by the Secret Service.他的信被特工处截获了。
• Gunmen intercepted him on his way to the airport.持枪歹徒在他去机场的路上截击了他。

8 vaccines   

疫苗，痘苗( vaccine的名词复数 )

参考例句：

• His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
• The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。

9 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。

10 invaders   

入侵者，侵略者，侵入物( invader的名词复数 )

参考例句：

• They prepared to repel the invaders. 他们准备赶走侵略军。
• The family has traced its ancestry to the Norman invaders. 这个家族将自己的世系追溯到诺曼征服者。

11 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。

12 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

13 dormant   

adj.暂停活动的；休眠的；潜伏的

参考例句：

• Many animals are in a dormant state during winter.在冬天许多动物都处于睡眠状态。
• This dormant volcano suddenly fired up.这座休眠火山突然爆发了。

14 primates   

primate的复数

参考例句：

• Primates are alert, inquisitive animals. 灵长目动物是机灵、好奇的动物。
• Consciousness or cerebration has been said to have emerged in the evolution of higher primates. 据说意识或思考在较高级灵长类的进化中已出现。

15 vaccinated   

[医]已接种的，种痘的，接种过疫菌的

参考例句：

• I was vaccinated against tetanus. 我接种了破伤风疫苗。
• Were you vaccinated against smallpox as a child? 你小时候打过天花疫苗吗？

16 unprecedented   

adj.无前例的，新奇的

参考例句：

• The air crash caused an unprecedented number of deaths.这次空难的死亡人数是空前的。
• A flood of this sort is really unprecedented.这样大的洪水真是十年九不遇。

17 formulate   

v.用公式表示；规划；设计；系统地阐述

参考例句：

• He took care to formulate his reply very clearly.他字斟句酌，清楚地做了回答。
• I was impressed by the way he could formulate his ideas.他陈述观点的方式让我印象深刻。