VOA标准英语2011--New Ebola Vaccine Proves Effective in Mice

New Ebola Vaccine¹ Proves Effective in Mice

 

U.S. scientists have developed a new vaccine against the deadly ebola virus which has the potential to remain potent² after years of storage.

Ebola is one of the deadliest viruses known. It kills about nine out of every 10 people it infects. Fortunately, outbreaks have been rare. But concern about more widespread infection, and the possibility of ebola being used as a biological weapon, have spurred research of a vaccine.

Several experimental vaccines³ were developed based on the ebola virus itself. But because the virus degrades over time, virus-based vaccines have to be stored at very cold temperatures, which can be expensive. And because they use the actual ebola virus, there are safety concerns as well.

So researchers in Arizona are trying something different. Their idea is, in effect, to trick the body's immune system into mounting a defense⁴ against ebola by making a vaccine based on material that's on the surface of the virus.

"We take the proteins that stick out and form spikes⁵ on the virus," explained University of Arizona scientist Melissa Herbst-Kralovetz. "They're called glycoproteins. And we fuse that to an antibody backbone⁶."

This colorized transmission electron micrograph (TEM) reveals some of the form and structure of an Ebola virus.

Co-researcher Charles Arntzen of Arizona State University says the protein-antibody particles attach to each other to form an "ebola immune complex" - or, as he put it, sort of a "glob."

"Turns out, whenever you have a complex of identical proteins like this, it's really a nice signal to our body to say, 'oh, this is unusual, it looks like a virus, what we need to do is mount an immune response against this complex,'" he says.

To make the glycoprotein-antibody material, the scientists used an unusual manufacturing process. They started with the DNA⁷ that contains the instructions for the spiky⁸ ebola surface protein, inserted it into a bacteria, and then dipped tobacco plants into a solution with the bacteria.

Arntzen says that reprograms the tobacco leaf cells. "And after about 10 days to 12 days, the tobacco plant starts to get looking very sick because it's diverting all of its energy into making our vaccine."

Herbst-Kralovetz says the experimental vaccine was tested on laboratory mice, who were exposed to live ebola virus. Combined with an adjuvant - a substance often added to make vaccines work better - she says four out of five mice were protected against the virus.

"So, 80 percent protection correlated with the best level of protection from another candidate vaccine. And so we were very happy with that."

And her colleague, Arntzen, says the vaccine can be dried to a powder, so it should survive long-term storage.

The next step, before beginning human trials, is testing the vaccine in non-human primates⁹.

The research is reported in the Proceedings¹⁰ of the National Academy of Sciences.

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 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。

3 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。

4 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

5 spikes   

n.穗( spike的名词复数 )；跑鞋；（防滑）鞋钉；尖状物v.加烈酒于( spike的第三人称单数 )；偷偷地给某人的饮料加入（更多）酒精（ 或药物）；把尖状物钉入；打乱某人的计划

参考例句：

• a row of iron spikes on a wall 墙头的一排尖铁
• There is a row of spikes on top of the prison wall to prevent the prisoners escaping. 监狱墙头装有一排尖钉，以防犯人逃跑。 来自《简明英汉词典》

6 backbone   

n.脊骨，脊柱，骨干；刚毅，骨气

参考例句：

• The Chinese people have backbone.中国人民有骨气。
• The backbone is an articulate structure.脊椎骨是一种关节相连的结构。

7 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

8 spiky   

adj.长而尖的，大钉似的

参考例句：

• Your hairbrush is too spiky for me.你的发刷，我觉得太尖了。
• The spiky handwriting on the airmail envelope from London was obviously hers.发自伦敦的航空信封上的尖长字迹分明是她的。

9 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。

10 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