Shortages of flu vaccine are nothing new in America, but this year' s is a whopper. Until

The foremost reason why the egg-based method is defective lies in_____.

[A] the complex process of vaccine production

[B] its potential threat to human being

[C] the low survival rate for new flu vaccines

[D] its contribution to the flu vaccine shortage

The foremost reason why the egg-based method is defective lies in_____.

[A] the complex process of vaccine production

[B] its potential threat to human being

[C] the low survival rate for new flu vaccines

[D] its contribution to the flu vaccine shortage

ast 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 re-sponse. 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.

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

What step is essential to the traditional production of flu vaccine？

[A] Manufacturers implant the vaccine into ordered chicken eggs.

[B] Scientists identify the exact strain soon after a flu pandemic starts.

[C] Public health measures are taken as an important pandemic-fighting tool.

[D] Viruses are deadened and made clean before being put into vaccine use.

Those who net the flu vaccine are surely protected from the disease

A．Right

B．Wrong

C．Not mentioned

Those who get the flu vaccine are surely protected from the disease.

A．Right

B．Wrong

C．Not mentioned

Those who net the flu vaccine are surely protected from the disease

A．Right

B．Wrong

C．Not mentioned

What is the author's attitude towards the newly developed bird flu vaccine？

A．Slightly approves of.

B．Depicts neutrally.

C．Slightly disapproves of.

D．Completely rejects.

Flu Shots Or Not？

It sounded like a good idea when New York City's mayor, Rudollph Giuliani, advised New Yorkers recently to get a flu shot. After all, 20,000 Americans each year die of influenza. And this year in particular, the mayor suggested, getting a flu shot might be an especially good idea, since it could help doctors distinguish between flu and the deadly inhalational (吸入的) form. of anthrax (炭疽). How？ Both anthrax and flu exhibit strikingly similar symptoms -- fever, chills and muscle aches -- in the early days of the infection. Physicians would be quick to suspect anthrax in anyone who was vaccinated (接种疫苗) against flu and still developed fever and chills. That would give them a better chance to identify any new victims of terror while their infection was still in its earliest, most treatable stages.

Or so the mayor's reasoning went. Unfortunately, there are a couple of problems with his logic. For one thing, getting vaccinated against influenza doesn't guarantee you won't get sick. Although highly effective, the flu vaccine (疫苗) protects against only the dominant types of the disease and even then does not provide 100% protection. It takes a couple of weeks for your body to respond to the vaccine with a sufficient number of antibodies (抗体). Each year thousands of Americans who get the vaccine nevertheless still get the flu.

There are also plenty of reasons you might develop fever, chills and muscle aches that have nothing to do with either anthrax or flu. indeed, doctors estimate that more than 80% of all flulike illnesses each winter are caused by other groups of viruses. Getting vaccinated against flu can't protect you against suffering from these other illnesses.

In the worst case, asking all healthy adults to get vaccinated could actually have the opposite effect to the one intended, leading to even more deaths if it means we run out of shots for those who are most vulnerable to the infection. Already there have been delays in getting this year's shipment of vaccine to clinics and doctors' offices. Those who should be at the front of the line include folks who are 65 or older, nursing-home residents and adults and children with chronic health problems as well as anyone who cares for or lives with such people. Flu shots are also important for men and women whose immune system is weakened by HIV (艾滋病病毒) or other conditions.

The best reason to get the flu vaccine is that it protects against most flus--not that you're worried about getting anthrax. While inhalational anthrax has killed only five people so far, many more could be at risk from flu-related complications. There's no need to worsen the tragedy by making this year's influenza epidemic any worse.

Quite a few New Yorkers took their mayor's recent advice and got a flu shot.

A．Right

B．Wrong

C．Not mentioned