科學家研发广谱流感疫苗一托福阅读机经背景.docxVIP

智课网TOEFL备考资料科学家研发广谱流感疫苗一托福阅读机经背景 Each year, scientists work to develop a unique influenza vaccine to protect people against the strain expected in the coming flu season. Mutations in the virus mean that last years vaccine probably wont protect against this years flu variety. Now, a team of U.S. scientists think theyre on track to developing a universal vaccine that will protect people against all kinds of influenza. 每年，科学家们都根据下一个流感季节的流感类型预测来研发一种专门的流感疫苗。流感病毒不断发生变异，去年的流感疫苗很可能无法对抗今年的流感类型。现在，一些美国科学家正在研发一种广谱疫苗，帮助人们预防任何类型的流感。 The standard flu vaccine causes the body to produces antibodies, which target parts of the virus that frequently mutate. But in a new study, researchers used a vaccine aimed at a different part of the virus. 典型的疫苗可以促使人体产生抗体，抵御病毒经常发生变异的那部分。现在，在一项新的研究中，研究人员使用了一种针对病毒不同部分的疫苗。 There are parts of the flu virus that could be the target of what we would hope eventually could be a universal influenza vaccine, said Gary Nabel, who heads the U.S. governments Vaccine Research Center at the National Institute of Allergy and Infectious Diseases of the National Institutes of Health and was the studys lead author. 美国国家卫生院所属国家过敏及传染病研究所的疫苗研究中心主任盖瑞·内伯尔说：“流感病毒中有些部分是我们的突破口，我们希望最终能够研发出一种广谱疫苗。病毒的这部分不会变异。” They dont mutate, and the reason they dont mutate is that if they try to, the virus cant survive if you have mutations in these sites. To get at these non-mutating parts of the virus, Nabel and his colleagues used a two-step vaccination process, called prime-boost. The first step uses a bit of influenza DNA to get the patients immune system to begin fighting off the flu, and then the protection is given a boost some time later by the second step, which can be either another bit of DNA or a conventional flu vaccine. 为了在病毒中分离这种“非变异”成分，内伯尔和他的同事们使用一个两步接种过程。第一步是使用少量流感NDA，使病患的免疫系统开始与流感对抗。稍过一阵，再采取第二步，通过再使用少量流感DNA或者一般的流感疫苗，来加强抵御能力。 In his paper, which was published online by the journal Science, Nabel describes the results of animal tests in ferrets and mice using the