[单项选择]Scientists said Thursday that a new AIDS vaccine, the first ever declared to protect a significant minority of humans against the disease, would be studied to answer two fundamental questions: why it worked in some people but not in others, and why those infected despite vaccination got no benefit at all.
The vaccine—known as RV 144, a combination of two genetically engineered vaccines, neither of which had worked before in humanslwas declared a qualified success after a six-year clinical trial on more than 16,000 volunteers in Thailand. Those who were vaccinated became infected at a rate nearly one-third lower than the others, the sponsors said Thursday morning.
"I don’t want to use a word like ’breakthrough,’ but I don’t think there’s any doubt that this is a very important result," said Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, which is one of the trial’s backers. "For more than 20 years now, vaccine trials have es
A. It has been on trial for six years.
B. People who get it are protected against AIDS.
C. People who get it are not as easily infected as others.
D. It is regarded as a very important finding in the history.

[单项选择]Scientists said Thursday that a new AIDS vaccine, the first ever declared to protect a significant minority of humans against the disease, would be studied to answer two fundamental questions: why it worked in some people but not in others, and why those infected despite vaccination got no benefit at all.
The vaccine—known as RV 144, a combination of two genetically engineered vaccines, neither of which had worked before in humanslwas declared a qualified success after a six-year clinical trial on more than 16,000 volunteers in Thailand. Those who were vaccinated became infected at a rate nearly one-third lower than the others, the sponsors said Thursday morning.
"I don’t want to use a word like ’breakthrough,’ but I don’t think there’s any doubt that this is a very important result," said Dr. Anthony S. Fauci, the director of the National Institute of Allergy and Infectious Diseases, which is one of the trial’s backers. "For more than 20 years now, vaccine trials have es
A. Experts know how to find out AIDS vaccine.
B. Experts start to produce RV 144 in large amounts.
C. Experts will soon find out a vaccine that will end AIDS.
D. Experts are convinced of the possibility of finding AIDS vaccin

[单项选择]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 re-emphasizes 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 fertil
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