首页
登录
职称英语
Modern technology has put men on the moon and deciphered the human genome. B
Modern technology has put men on the moon and deciphered the human genome. B
游客
2023-08-21
54
管理
问题
Modern technology has put men on the moon and deciphered the human genome. But when it comes to brewing up flu to make vaccines, science still turns to the incredible edible egg. Ever since the 1940s, vaccine makers have grown large batches of virus inside chicken eggs. New cell-based technologies are in the pipeline, however, and may finally get the support they need now that the United States is faced with a critical shortage of flu vaccine. Although experts disagree on whether new ways of producing vaccine(疫苗)could have prevented a shortage like the one happening today, there is no doubt that the existing system has serious flaws.
Each year, vaccine manufacturers place advance orders for millions of specially grown chicken eggs. Meanwhile, Public Health officials monitor circulating strains of flu, and each March they recommend three strains—two influenza A strains and one B strain—for manufacturers to include in vaccines. In the late spring and summer, automated machines inject virus into eggs and later suck out the influenza-rich goop. Virus from the eggs’ innards gets killed and processed to remove egg proteins and other contaminants before being packaged into vials for fall shipment.
Why has this egg method persisted for six decades? The main reason is that it’s reliable. But even though the eggs are reliable, they have serious drawbacks. One is the long lead time needed to order the eggs. That means it’s hard to make more vaccine in a hurry, in case of a shortage or unexpected outbreak. And eggs may simply be too cumbersome(大量的)to keep up with the hundreds of millions of doses required to handle the demand for flu vaccine.
What’s more, some flu strains don’t grow well in eggs. Last year, scientists were unable to include the Fujian strain in the vaccine formulation. It was a relatively new strain, and manufacturers simply couldn’t find a quick way to adapt it so that it grew well in eggs. "We knew the strain was out there," recalls Theodore Eickhoff of the University of Colorado Health Sciences Center, " but public-health officials were left without a vaccine—and, consequently, a more severe flu season. "
Worse, the viruses that pose the greatest threat might be hardest to grow in eggs. That’s because global pandemics like the one that killed over 50 million people between 1918 and 1920 are thought to occur when a bird influenza changes in a way that lets it cross the species barrier and infect humans. Since humans haven’t encountered the new virus before, they have little protective immunity. The deadly bird flu circulating in Asia in 1997 and 1998, for example, worried Public Health officials because it spread to some people who handled birds and killed them— although the bug never circulated among humans. But when scientists tried to make vaccine the old-fashioned way, the bird flu quickly killed the eggs. [br] The moon-landing is mentioned in the first paragraph to illustrate that ______.
选项
A、technology cannot solve all of our human problems
B、progress in vaccine research for influenza has lagged behind
C、great achievements have been made by men in exploring the unknown
D、the development of vaccine production methods can not be stopped
答案
B
解析
由题干关键词moon—landing定位到第一段第一、二句。这两句话形成鲜明的对比,说明目前流感疫苗的生产方式还很落后。因此B)正确。
转载请注明原文地址:https://tihaiku.com/zcyy/2943594.html
相关试题推荐
[originaltext]Themodernsailingshipwasdevelopedbyamanwhoneverwent
[originaltext]Themodernsailingshipwasdevelopedbyamanwhoneverwent
SydneyOperaHousemustbeoneofthemostrecognizableimagesofthemodern
SydneyOperaHousemustbeoneofthemostrecognizableimagesofthemodern
SydneyOperaHousemustbeoneofthemostrecognizableimagesofthemodern
SydneyOperaHousemustbeoneofthemostrecognizableimagesofthemodern
SydneyOperaHousemustbeoneofthemostrecognizableimagesofthemodern
SydneyOperaHousemustbeoneofthemostrecognizableimagesofthemodern
Newtechnologylinkstheworldasneverbefore.Ourplanethas【B1】______.It’
Newtechnologylinkstheworldasneverbefore.Ourplanethas【B1】______.It’
随机试题
HowtoTametheAngerMonsterThreefactorscausing
[originaltext]WhenMr.Finchretired,heboughtasmallcottageinaseaside
Therearetwotypesofpeopleintheworld.Althoughtheyhaveequaldegrees
[originaltext]BeforeWorldWarn,wespentoursummerholidaysinHungary.
阅读下列文字,回答有关问题。 所谓媒体,是英文media的译名,也称媒介,是载
以下关于董事会的职权说法正确的有( )A.决定公司的经营方针和投资计划
四个相同的盒子里各有3个球,其中一个盒子里放了3个红球,一个盒子里放了2个红球1
影响房地产价格的经济因素有()。A.经济发展状况、储蓄、消费、投资水平
消防救援机构于2020年8月对某商业综合体进行检查时,发现的下列灭火器中应进行报
电站汽轮机低压外上缸组合安装正确的程序是()。A.检查水平、垂直结合面间隙
最新回复
(
0
)