英語聽力文摘473 疫苗如何培育的？
Vaccine makers crack the eggshell and inject the virus into the white stuff surrounding the yolk. Then they reseal the egg, the embryo becomes infected, and the virus is allowed to copy itself trillions of times over. And they use eggs because eggs are easy to infect and are relatively cheap. Right?
M: Well，yeah，But...
W: But the problem with using eggs to make flu vaccines is that normally there are plenty of eggs to go around, but when there’s a sudden outbreak the eggs can run out pretty fast. And that’s one of the reasons why researchers are experimenting with a new way to grow flu vaccines.
Instead of infecting eggs, they’re trying to grow flu viruses in cultured human and animal cells. When an epidemic occurs, doctors could simply grow a large colony of cells, and then more easily develop enough vaccine.
And this method may not only save time, but also potentially produce more effective vaccines. Since the vaccine grown in cells may be better than caccine grown in the eggs at mimicking the flu virus that infects people.
疫苗生產(chǎn)商打碎蛋殼，把病毒注入蛋黃周圍的蛋清里邊。然后他們再把雞蛋密封起來，這樣雞胚就被感染了，病毒就可以上萬億次的繁殖。他們使用雞蛋培育疫苗是因為雞胚很容易被感染而且還很便宜，是吧?
是的，但是...
使用雞蛋培育流感疫苗的問題是，正常來說要有很多雞蛋才行，但假如疾病突然發(fā)生，雞蛋很快就會用完。那也是為什么研究員們正嘗試培育流感疫苗新方法的原因之一。
他們正試圖在人類和動物細胞里培育流感疫苗，而不是去感染雞蛋。當(dāng)傳染病發(fā)生時，醫(yī)生可以僅僅是培育一大群細胞，然后很輕易地生產(chǎn)足夠的疫苗。
而且這種方法不僅節(jié)約時間，還能盡可能多地生產(chǎn)有效的疫苗，因為細胞里生長的疫苗在仿制流感病毒方面要比雞蛋里的好。
