单选题 Shortages of flu vaccine are nothing new in America, but this year' s is a whopper. Until last week, it appeared that 100 million Americans would have access to flu shots this fall. Then British authorities, concerned about quality-control problems at a production plant in Liverpool, barred all further shipments by the Chiron Corp. Overnight, the U.S. vaccine supply dwindled by nearly half and federal health officials found themselves making an unusual plea. Instead of beseeching us all to get vaccinated, they' re now urging most healthy people between the ages of 2 and 64 not to. "This reemphasizes the fragility of our vaccine supply," says Dr. Martin Myers of the National Network for Immunization Information, "and the lack of redundancy in our system."
Why is such a basic health service so easily knocked out? Mainly because private companies have had little incentive to pursue it. To create a single dose of flu vaccine, a manufacturer has to grow live virus in a 2-week-old fertilized chicken egg, then crack the egg, harvest the virus and extract the proteins used to provoke an immune response. Profit margins are narrow, demand is fickle and, because each year's flu virus is different, any leftover vaccine goes to waste. As a result, the United States now has only two major suppliers ( Chiron and Aventis Pasteur)--and when one of them runs into trouble, there isn' t much the other can do about it. "A vaccine maker can't just call up and order 40 million more fertilized eggs," says Manon Cox, of Connecticut-based Protein Sciences Corp. "There's a whole industry that's scheduled to produce a certain number of eggs at a certain time. "
Sleeker technologies are now in the works, and experts are hoping that this year's fiasco will speed the pace of innovation. The main challenge is to shift production from eggs into cell cultures--a medium already used to make most other vaccines. Flu vaccines are harder than most to produce this way, but several biotech companies are now pursuing this strategy, and one culture-based product (Solvay Pharmaceuticals' Invivac) has been cleared for marketing in Europe.
For Americans, the immediate challenge is to make the most of a limited supply. The government estimates that 95 million people still qualify for shots under the voluntary restrictions announced last week. That' s nearly twice the number of doses that clinics will have on hand, but only 60 million Americans seek out shots in a normal year. In fact, many experts are hoping the shortage will serve as an awareness campaign--encouraging the people who really need a flu shot to get one.
单选题 Shortages of flue vaccine show that ______.
  • A. America relies too much on foreign suppliers
  • B. the demand of flue vaccines is high this year
  • C. quality problem is a serious problem in flu vaccine production
  • D. the supply of flu vaccines is rather weak and America has no back-up measures to make it up
【正确答案】 D
【答案解析】[解析] 第一段最后一句话指出了疫苗短缺所暴露出来的问题。“This reemphasizes the fragility of our vaccine supply．”says Dr．Martin Myers of the National Network for Immunization Information，“and the lack of redundancy in our system．”“这再次凸显出我们疫苗供应的脆弱性，”全国免疫信息网的马丁·迈尔斯医生说，“此外，我们也没有必要的补救机制。”因此正确答案为D。
单选题 The word "cleared" (Line 4, Paragraph 3) might mean ______.
  • A. permitted
  • B. removed
  • C. proved
  • D. produced
【正确答案】 A
【答案解析】[解析] 在第三段最后一句“…one culture-based product has been cleared for marketing in Europe．”里出现了“cleared”一词。根据下文中“marketing”和读者有关药品上市前应该得到批准的常识，可以判断出，该词在本句中的意思是“得到官方的批准”。因此正确答案为A。
单选题 Private companies have little interest in producing flu vaccines because of ______.
  • A. complicated process, high cost, low profit and high risk
  • B. shortages of fertilized chicken eggs
  • C. difficulty in growing live virus
  • D. fast changing of flu virus
【正确答案】 A
【答案解析】[解析] 第二段第二句“Mainly because private companies have had little incentive to pursue it．”意思是说“私企生产流感疫苗的积极性不高”。接下来作者介绍了制作疫苗的复杂工序，由此可以推断出流感疫苗生产工艺复杂、成本高。第二段又明确指出了私企不愿意生产流感疫苗的其他原因：利润率低、需求不稳定、此外由于流感病毒每年都不同，因此生产数量不能过大，由此也可推断出生产的风险性大，如果生产多了就会损失很大。因此正确答案为A。
单选题 From the last paragraph we can infer that ______.
  • A. the government hopes to solve the problem by way of volunteer restrictions
  • B. more than 47 million Americans who are qualified to get flu vaccine shots can not get them this year
  • C. America has to deal with a limited supply of flu vaccines this year
  • D. normally only a small percentage of American population gets flu vaccine shots each year
【正确答案】 B
【答案解析】[解析] 由第四段第二句“The government estimates that 95 million people still qualify for shots under the voluntary restrictions announced last week．”中可以知道大约有九千五百万人有资格注射疫苗。根据第四段第三句：“That's nearly twice the number of doses that clinics will have on hand，but only 60 million Americans seek out shots in a normal year．”和前一句可以推断出美国现有大约四千七百万份流感疫苗库存，由此可推断出美国至少还有四千七百多万有资格注射疫苗的人无法得到注射。因此正确答案为B。
单选题 According to the passage, which of the following is TRUE?
  • A. All Americans are persuaded not to get vaccinated this year.
  • B. The big problem in innovating flu vaccine producing technique is how to grow virus in a new way.
  • C. More flu vaccines can not be produced in a short time because private companies refuse to produce more.
  • D. Flu vaccines are easier than most vaccines to produce through cell cultures.
【正确答案】 B
【答案解析】[解析] 由第一段的“Instead of beseeching us all to get vaccinated，they're now urging most healthy people between the ages of 2 and 64 not to．”可以判断出美国之呼吁2至64岁的健康人不接种流感疫苗，而不是所有的美国人，因此答案A是错误的。从第二段最后一句话可以看出疫苗生产厂家无法临时增加疫苗生产不是由于他们不愿意，而是由于受精鸡蛋的生产已经预先计划好，无 法提供更多的受精鸡蛋，由此可见答案C是错误的。从第三段第三行“Flu vaccines are harder than most to produce this way”可以判断出答案D是错误的，因为流感疫苗比别的疫苗更难用细菌培育的方式生产。而由第三段第2—3行“The main challenge is to shift production from eggs into cell cultures—a。medium already used to make most other vaccines．”以及上一句可见，改造疫苗生产工艺的关键在于革新病毒培育技术。因此正确答案为B。