VOA慢速英语2020 信使核糖核酸：两大新冠疫苗背后的技术

It takes years of research and testing to produce a vaccine¹. But scientists are hopeful that a technology called messenger RNA, or mRNA, could produce a safe and effective vaccine against COVID-19 by the end of the year.

疫苗生产需要经过多年的研究和测试。但是科学家们希望在今年年底前，一种名为信使核糖核酸（mRNA）的技术可以生产出安全有效的新冠肺炎疫苗。

The World Health Organization (WHO) says there are 11 COVID-19 vaccine candidates currently undergoing Phase 3 trials around the world. The trials involve large groups of volunteers. Some receive the experimental vaccine while others are given an inactive substance called a placebo².

世卫组织表示，目前全球有11种候选新冠肺炎疫苗正在进行3期试验。这些试验涉及了大量志愿者。有些志愿者接种了实验性疫苗，另一些则接种了被称为安慰剂的非活性物质。

Among the most promising³ vaccine candidates are two that use mRNA technology. Those experimental vaccines⁴ come from American drug-makers Moderna and Pfizer. Pfizer is partnered with German company BioNTech on the project.

在最有前途的候选疫苗中，有两种采用了信使核糖核酸技术。这些实验性疫苗来自美国制药商莫德纳公司和辉瑞公司。辉瑞跟德国BioNTech公司合作进行了这个项目。

On Monday, Nov. 9, Pfizer and BioNTech announced that their mRNA-based experimental vaccine appears to be more than 90 percent effective in preventing COVID-19.

11月9日的周一，辉瑞和BioNTech公司宣布，他们基于信使核糖核酸技术开发的实验性疫苗在预防新冠肺炎方面的有效性似乎超过了90%。

The partnership⁵ said the early finding involved 94 volunteers in the trial who developed COVID-19. About 44,000 volunteers took part in the late Phase 3 study. An independent group of scientists called the Data Safety Monitoring Board examined the study.

这两家合作公司表示，早期结果有94名志愿者在这期试验中感染了新冠肺炎。大约有44000名志愿者参加了最后的3期试验。一个名为数据安全监测委员会的独立科学家小组对该研究进行了审查。

Pfizer and BioNTech also said they have found no serious safety concerns in the testing so far. They expect to seek emergency use permission from the U.S. Food and Drug Administration (FDA) later this month. The agency requires a vaccine be at least 50 percent effective for emergency use.

辉瑞和BioNTech公司还表示，到目前为止，他们在试验中并未发现严重的安全隐患。他们希望本月晚些时候获得美国食品和药品管理局的紧急使用授权。该机构要求疫苗的紧急使用至少要有50%的有效率。

Dr. Anthony Fauci is the U.S. government's top infectious diseases expert. He called the safety result of Pfizer and BioNTech's study "extraordinary."

福奇博士是美国政府最顶级的传染病专家。他称辉瑞和BioNTech公司的安全性结果“非同寻常。”

"Not very many people expected it would be as high as that," he said.

他说：“很多人并没预料到会有这么高。”

Dr. Bruce Aylward is a top adviser⁶ at the WHO. He said Pfizer's vaccine could "fundamentally change the direction of this crisis."

布鲁斯·艾尔沃德博士是世卫组织的顶级顾问。他说辉瑞公司的疫苗可能“从根本上改变这场危机的发展方向。”

Two days later, Massachusetts-based Moderna announced that it is preparing to send its Phase 3 study to the Data Safety Monitoring Board. Moderna said it has more than 53 cases of COVID-19 infections out of 30,000 volunteers.

两天之后，位于马萨诸塞州的莫德纳公司宣布，该公司正准备将其3期试验发给数据安全监测委员会。莫德纳公司表示，在3万名志愿者中，已有53例新冠肺炎感染病例。

Fauci told the Financial Times that he expected good results from Moderna's study because the two mRNA-based vaccines are "identical in many respects."

福奇对英国《金融时报》表示，他预期莫德纳公司的试验会取得良好的结果，因为这两种信使核糖核酸疫苗“在许多方面相同。”

What is mRNA?

什么是信使核糖核酸？

The U.S. Centers for Disease Control and Prevention says vaccines usually contain an inactive or weakened virus. Vaccines introduce a virus to the body to force the production of antibodies that fight the virus.

美国疾病预防和控制中心表示，疫苗通常含有无活性或是弱化的病毒。疫苗将病毒引入人体，以迫使人体产生抵抗该病毒的抗体。

Both Pfizer and Moderna's vaccines are made with mRNA technology. They do not contain the coronavirus itself. To make an mRNA vaccine, scientists create a genetic⁸ material that directs the human body to produce antibodies that can recognize and destroy the coronavirus.

辉瑞公司和莫德纳公司的疫苗都采用了信使核糖核酸技术。它们不包含新冠病毒本身。为了生产信使核糖核酸疫苗，科学家们创造了一种遗传物质，指导人体产生可识别和破坏新冠病毒的抗体。

No mRNA product has been approved to treat people. Research in the technology started nearly 30 years ago.

目前尚没有信使核糖核酸产品被批准用于治疗患者。这项技术的研究始于近30年前。

In 1990, University of Pennsylvania scientist Katalin Karikó proposed using mRNA technology in gene⁷ therapy. At the time, the technology was difficult to work with. When she injected lab mice with the genetic material, some died.

1990年，宾夕法尼亚大学的科学家凯特琳·卡瑞克提出在基因治疗中采用信使核糖核酸技术。当时该技术很难应用。当她向小白鼠注射遗传物质时，有些小白鼠死了。

Karikó worked with colleague Drew Weissman. They made a critical discovery in 2005. They replaced one of mRNA's four chemical building blocks with a slightly modified compound called pseudouridine. Weissman said, "We submitted that for a patent, and that was the birth of therapeutic⁹ RNA."

卡瑞克与同事德鲁·韦斯曼一起合作。他们在2005年做出了一项重大发现。他们用一种经过轻微修饰的化合物假尿嘧啶核苷替换了信使核糖核酸中4个化学组成部分之一。韦斯曼表示：“我们提交了一项专利，这就是治疗性信使核糖核酸的诞生。”

Karikó now works for BioNTech supervising development of its mRNA product.

卡瑞克目前在BioNTech公司负责监督其信使核糖核酸产品的开发。

Karikó and Weissman's findings, however, did not receive much attention until 2010. That year, Harvard University scientist Derrick Rossi used modified mRNA in his stem cell research. Rossi, along with several others, licensed¹⁰ the technology to establish a new biotech drug-maker called Moderna. The name is a combination of the words modified and RNA.

然而，卡瑞克和韦斯曼的发现直到2010年才受到关注。那年，哈佛大学的科学家德里克·罗西在他的干细胞研究中使用了经过修饰的信使核糖核酸。罗西与其它几家公司一起获得了这项技术的许可，从而建立了一家名为莫德纳的新型生物技术制药公司。这个公司名称结合了modified 和 RNA这两个单词。

Rossi is no longer with Moderna but he credited Karikó and Weissman with the mRNA discovery. He told the medical website Stat that the two researchers deserve the Nobel Prize in chemistry.

罗西不再就职于莫德纳公司，但是他将信使核糖核酸的发现归功于卡瑞克和韦斯曼。他对Stat医学网站表示，这两位研究人员应获颁诺贝尔化学奖。

"If anyone asks me whom to vote for some day down the line, I would put them front and center," he said. "That fundamental discovery is going to go into medicines that help the world."

他说：“如果有人问我有一天在这个研究方向上会把票投给谁，我会把他们放在最重要的位置。这一基础发现将被用于拯救世界的药物中。”

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 placebo   

n.安慰剂；宽慰话

参考例句：

• The placebo has been found to work with a lot of different cases.人们已发现安慰剂能在很多不同的病例中发挥作用。
• The placebo effect refers to all the observable behaviors caused by placebo.安慰剂效应是指由安慰剂所引起的可观察的行为。

3 promising   

adj.有希望的，有前途的

参考例句：

• The results of the experiments are very promising.实验的结果充满了希望。
• We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。

4 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。

5 partnership   

n.合作关系，伙伴关系

参考例句：

• The company has gone into partnership with Swiss Bank Corporation.这家公司已经和瑞士银行公司建立合作关系。
• Martin has taken him into general partnership in his company.马丁已让他成为公司的普通合伙人。

6 adviser   

n.劝告者，顾问

参考例句：

• They employed me as an adviser.他们聘请我当顾问。
• Our department has engaged a foreign teacher as phonetic adviser.我们系已经聘请了一位外籍老师作为语音顾问。

7 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。

8 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。

9 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。

10 licensed   

adj.得到许可的v.许可，颁发执照(license的过去式和过去分词)

参考例句：

• The new drug has not yet been licensed in the US. 这种新药尚未在美国获得许可。
• Is that gun licensed? 那支枪有持枪执照吗？