Scientists Hurry to Develop Vaccine for China’s Pig Disease

 

Scientists are working to stop a deadly virus that infects pigs.

The virus is causing huge losses for farmers in China and other Asian countries.

Many farmers have tried to contain African swine flu by quarantining pigs and destroying infected animals. But the spread of the disease into East Asia has intensified¹ the search for other ways to deal with the problem.

The virus had not been considered a major concern for researchers until it appeared in China last year. Chinese farmers raise about half of the world’s pigs. Some researchers think the virus might have come from infected animals in Eastern Europe or Russia.

Since then, it has spread to China, Vietnam and other Asian countries. Millions of pigs have been destroyed.

Although swine flu does not sicken people, it is very contagious² and deadly to pigs.

A ‘global threat’ to a big industry

“Today’s situation, where you have this global threat, puts a lot more emphasis on this research,” said Doctor Luis Rodriguez. He spoke³ to The Associated Press.

Rodriguez leads the United States government laboratory for foreign animal diseases at Plum Island, New York.

Vaccines⁵ often are developed by killing⁶ a virus before it is injected into an animal. The disabled virus does not make the animal sick, but it activates⁷ the body’s natural defenses against disease. The immune system is then able to identify the virus and produce antibodies against it.

However, this method is not effective with all viruses including the one that causes African swine flu.

For swine flu, scientists have been working on a different kind of vaccine⁴. It is made from a weakened virus, not a dead one. The problem for researchers has been how to change the virus so it can be safely used.

Vietnam’s government reported a few weeks ago that it was testing vaccines, but provided few details of its programs.

In China, the government said scientists are working on a vaccine that genetically⁸ changes the virus. That is similar to a method being used by scientists in the United States.

The U.S. Department of Agriculture said it recently signed an agreement with a vaccine manufacturer to study and develop one of three possible vaccines from the Plum Island center. All the experimental vaccines use genetically changed viruses which have some of the genes⁹ removed.

But the vaccine finally chosen by researchers needs to be tested in large numbers of pigs before it is ready for approval.

Linda Dixon is a biologist at Britain’s Pirbright Institute, which studies diseases in farm animals. She said the testing can take from two to five years.

Even if vaccines become available, it is not clear if they will work everywhere. For example, vaccines developed for the virus in China and Europe may not work in African countries south of the Sahara desert, where the disease has existed much longer.

Daniel Rock once led Plum Island’s African swine flu program. He suggested that some areas might have more success against the disease by killing sick animals.

But Rock noted¹⁰ that the disease’s huge outbreaks around the world have made developing a vaccine an important goal for U.S. researchers.

I’m Mario Ritter Jr.

Words in This Story

quarantine – v. to remove or separate from other people or animals

contagious – adj. spreading from one person or organism to another

emphasis – n. special importance or attention given to some matter

immune system – n. the system that protects the body from diseases and infections

antibodies – n. substances produced by the body that fight disease

1 intensified   

v.（使）增强， （使）加剧( intensify的过去式和过去分词 )

参考例句：

• Violence intensified during the night. 在夜间暴力活动加剧了。
• The drought has intensified. 旱情加剧了。 来自《简明英汉词典》

2 contagious   

adj.传染性的，有感染力的

参考例句：

• It's a highly contagious infection.这种病极易传染。
• He's got a contagious laugh.他的笑富有感染力。

3 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

4 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。

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 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

7 activates   

使活动，起动，触发( activate的第三人称单数 )

参考例句：

• Activates the window and displays it in its current size and position. 激活窗口，保持当前的大小及位置不变。
• Pulling out the alarm switch activates alarm and pushing it deactivates it. 闹钟的开和关是通过拔出和按入闹铃开关实现的。

8 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

9 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

10 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。