VOA标准英语2011--Potent Antibodies Offer New AIDS Vaccine

Potent¹ Antibodies Offer New AIDS Vaccine² Design

Researchers say powerful antibodies may hold clues to developing an effective AIDS vaccine. The antibodies were isolated³ from individuals already infected with HIV.
Dr. Wayne Koff says the goal is to find a vaccine that will help the immune system fend⁴ off an HIV infection.
“Most vaccines⁵ work in terms of stimulating⁶ something known as antibody, which is a protein substance in the body. And they work because the antibody identifies the site on the virus. And it can attach onto the virus and kill it,” he said.
Koff, chief scientific officer for IAVI, the International AIDS Vaccine Initiative, said the problem with HIV is that it’s a hyper-variable virus.
That means it’s different all over the world. And so instead of a single strain or a couple of strains, we have millions of strains. And as a result, for a vaccine, instead of eliciting⁷ a neutralizing⁸ antibody, what one is attempting to do is to identify where the vulnerable sites on the virus that are the same on every virus particle. And these antibodies then are known as broadly neutralizing antibodies. So if you’re exposed to a virus on one side of the globe, they would work just as well as if you’re exposed in some other region of the world.
HIV becomes hyper-variable when it replicates⁹. Each time, it’s just a little bit different. Some scientists call these changes minor¹⁰ errors, but it’s enough to confound the human immune system. The changes occur in the outer protein of the virus, the target of neutralizing antibodies. In other words, the weak spot.
Only a few have them
The 17 antibodies that were isolated came from people infected with HIV.
Koff said, “We screened about 1,800 people. About one percent of the individuals had extremely broad and potent neutralizing antibodies against HIV. We then went back to these individuals and we took additional samples of blood and from those individuals we identified these broadly neutralizing antibodies.”
Did the people who produced these antibodies do better at fighting HIV? No, they didn’t.
“Most people would think if one has broadly neutralizing antibodies after HIV infection there should be a benefit. And that is not the case. In the case of individuals that are already HIV infected, the virus is always one step in front of the immune system,” he said.
But the immune system could react differently if it had these antibodies before infection.
“The real challenge for us and from a vaccine point of view is to ensure that the immune system is primed in advance of the virus as opposed to after HIV infection. It remains¹¹ to be seen if these antibodies will have any therapeutic¹² benefit,” he said.
Now what?
The next step is animal studies. The antibodies will be given to chimpanzees to see whether they can block an HIV-like virus. Koff says initial vaccine candidates will probably be ready in three or four years.
The antibody research is outlined in an article in Nature magazine. It was funded by IAVI, The Scripps Research Institute, Theraclone Sciences and Monogram¹³ Biosciences, Incorporated.

1 potent   

adj.强有力的，有权势的；有效力的

参考例句：

• The medicine had a potent effect on your disease.这药物对你的病疗效很大。
• We must account of his potent influence.我们必须考虑他的强有力的影响。

2 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。

3 isolated   

adj.与世隔绝的

参考例句：

• His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
• Patients with the disease should be isolated. 这种病的患者应予以隔离。

4 fend   

v.照料（自己），（自己）谋生，挡开，避开

参考例句：

• I've had to fend for myself since I was 14.我从十四岁时起就不得不照料自己。
• He raised his arm up to fend branches from his eyes.他举手将树枝从他眼前挡开。

5 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。

6 stimulating   

adj.有启发性的，能激发人思考的

参考例句：

• shower gel containing plant extracts that have a stimulating effect on the skin 含有对皮肤有益的植物精华的沐浴凝胶
• This is a drug for stimulating nerves. 这是一种兴奋剂。

7 eliciting   

n. 诱发, 引出 动词elicit的现在分词形式

参考例句：

• He succeeded in eliciting the information he needed from her. 他从她那里问出了他所需要的信息。
• A criminal trial isn't a tribunal for eliciting the truth. 刑事审讯并非是一种要探明真相的审判。

8 neutralizing   

v.使失效( neutralize的现在分词 )；抵消；中和；使（一个国家）中立化

参考例句：

• This juice-about a quart a day--pours into my duodenum, neutralizing acids. 这种消化液（每天约分泌1品脱）流入我的十二指肠，把酸中和了。 来自辞典例句
• AIM: To verify the role of a synthetic peptide in neutralizing endotoxins. 目的：检验一条合成肽在中和内毒素活性方面的作用。 来自互联网

9 replicates   

复制( replicate的第三人称单数 )； 重复； 再造； 再生

参考例句：

• The bluetongue virus replicates in the insect. 蓝舌病病毒在这种昆虫体内繁殖。
• The chameleon's skin replicates the pattern of its surroundings. 变色龙的皮肤可随环境的模式而改变颜色。

10 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。

11 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。

12 therapeutic   

adj.治疗的，起治疗作用的；对身心健康有益的

参考例句：

• Therapeutic measures were selected to fit the patient.选择治疗措施以适应病人的需要。
• When I was sad,music had a therapeutic effect.我悲伤的时候，音乐有治疗效力。

13 monogram   

n.字母组合

参考例句：

• There was a monogram in the corner in which were the initials"R.K.B.".原来手帕角上有个图案，其中包含着RKB三个字母。
• When we get married I don't have to change the monogram on my luggage.当我们结婚后，我连皮箱上的字母也不用改。