VOA慢速英语--新变异新冠病毒让专家们忧心忡忡

The fight against the virus that causes COVID-19 has taken a new turn: Reports of mutations are appearing quickly.

Many scientists fear that a variant² of the new coronavirus may appear that cannot be prevented by a known treatment or vaccine³.

The genes⁴ of the coronavirus are changing, and health officials say the high number of new cases is the main reason. Each new infection gives the virus a chance to mutate as it makes copies of itself. Each mutation¹ threatens to undo⁵ the progress made in the last year of fighting the pandemic.

On Friday, the World Health Organization urged more efforts to find new variants⁶. The U.S. Centers for Disease Control and Prevention said a new variant first identified in Britain a few months ago might become the number one virus in the U.S. by March. It does not cause more severe illness, but it could cause more hospitalizations and deaths. The CDC warned of coming "exponential growth."

"We're taking it really very seriously," Dr. Anthony Fauci said on American television Sunday. He is the U.S. government's top infectious⁷ disease expert.

"We need to do everything we can now...to get transmission⁸ as low as we possibly can," said Harvard University's Dr. Michael Mina. He said that the best way to stop mutations is to slow the spread of the virus.

So far, vaccines⁹ remain effective. There are, however, signs that some tests and drug treatments may not work with the new variants.

The virus may create a mutation that makes it more dangerous, said Dr. Pardis Sabeti. She is an evolutionary¹⁰ biologist at the Broad Institute of MIT and Harvard.

For example, younger people may not be afraid of the virus because it does not make them very sick. That could change quickly, she warned.

More reports of mutations

It is normal for viruses to mutate. A mutation that strengthens the virus helps it to survive by pushing out the weaker variants.

Just a few months after the coronavirus was discovered, a mutation called D614G began to spread. It quickly became a major form of the virus.

Trevor Bedford is a biologist with the Fred Hutchinson Cancer Research Center in Seattle. Last week, he wrote on Twitter, now, "we've started to see some striking¹¹ evolution" of the virus.

New variants have also been found in South Africa and Brazil. A main mutation in the variant identified in Britain appears to be in another variant that was found in Ohio, said Dan Jones. He is a molecular¹² pathologist at Ohio State University who announced that finding last week.

This is important because it does not appear the mutation was created as the result of travel. Rather, the virus may mutate in the same way in different places, Jones said.

That also means that travel restrictions¹³ might be ineffective, Mina said. Because the United States has so many cases, "we can breed our own variants that are just as bad or worse" as those in other countries, he said.

Treatment, vaccine, reinfection risks

Government scientists are "actively¹⁴ looking" into the possibility that variants found in South Africa and Brazil may be able to fight off antibody drugs and other treatments that can help people survive COVID-19, Dr. Janet Woodcock of the U.S. Food and Drug Administration told reporters Thursday.

Other scientists are not as worried. Dr. Andrew Pavia of the University of Utah said vaccines in use now should remain effective. They may need a small change to fight mutations.

Even then, he said, "it's probably going to be on the order of years if we use the vaccine well rather than months." He was speaking Thursday on a webcast run by the Infectious Diseases Society of America.

Words in This Story

mutate – v. to cause a change that creates a different quality in a living thing

variant – n. different in some way from others of the same kind

exponential – adj. very fast, to a very great degree

transmission – n. the process of something spreading, going from one place to another

evolution – n. the process by which living things change over time

pathologist – n. a part of medicine that seeks to find out causes

1 mutation   

n.变化，变异，转变

参考例句：

• People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
• So far the discussion has centered entirely around mutation in the strict sense.到目前为止，严格来讲，讨论完全集中于围绕突变问题上。

2 variant   

adj.不同的，变异的；n.变体，异体

参考例句：

• We give professional suggestions according to variant tanning stages for each customer.我们针对每位顾客不同的日晒阶段，提供强度适合的晒黑建议。
• In a variant of this approach,the tests are data- driven.这个方法的一个变种，是数据驱动的测试。

3 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。

4 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

5 undo   

vt.解开，松开；取消，撤销

参考例句：

• His pride will undo him some day.他的傲慢总有一天会毁了他。
• I managed secretly to undo a corner of the parcel.我悄悄地设法解开了包裹的一角。

6 variants   

n.变体( variant的名词复数 )；变种；变型；（词等的）变体

参考例句：

• Those variants will be preserved in the'struggle for existence". 这些变异将在“生存竞争”中被保留下来。 来自辞典例句
• Like organisms, viruses have variants, generally called strains. 与其他生物一样，病毒也有变种，一般称之为株系。 来自辞典例句

7 infectious   

adj.传染的，有传染性的，有感染力的

参考例句：

• Influenza is an infectious disease.流感是一种传染病。
• What an infectious laugh she has!她的笑声多么具有感染力啊！

8 transmission   

n.播送，发射，传送，传递，传染

参考例句：

• When the transmission is good,foreign stations can be heard.在传送情况良好时，以收到外国电台。
• The letter was delayed in transmission.这封信在传递中被耽误了。

9 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。

10 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

11 striking   

adj.显著的，惹人注目的，容貌出众的

参考例句：

• There is a striking difference between Jane and Mary.简和玛丽之间有显著的差异。
• What is immediately striking is how resourceful the children are.最令人注目的是孩子们的机智聪明。

12 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

13 restrictions   

约束( restriction的名词复数 )； 管制； 制约因素； 带限制性的条件（或规则）

参考例句：

• I found the restrictions irksome. 我对那些限制感到很烦。
• a snaggle of restrictions 杂乱无章的种种限制

14 actively   

adv.积极地，勤奋地

参考例句：

• During this period all the students were actively participating.在这节课中所有的学生都积极参加。
• We are actively intervening to settle a quarrel.我们正在积极调解争执。