2006年VOA标准英语-US University Scientists Work on Bird Flu

By Barry Unger
Washington, DC
03 February 2006
 
watch Bird Flu Research report

There are two new, experimental vaccines 2 against bird flu that both make use of a cold virus and that both may work even if the bird flu virus mutates.

In a study published in a British medical journal (the Lancet) researchers in the U.S. used a human cold virus, or adenovirus that was changed so it could not make copies of itself, to produce a bird flu protein that seems to stimulate 3 a more powerful immune response than normal flu vaccines. Both it and a vaccine 1 developed at the University of Pittsburgh can be produced more quickly than traditional vaccines as well, because they are not cultured in eggs. The Pittsburgh researchers used the cold virus and bird flu DNA 4 to immunize mice and chickens.

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The deadly strain of the bird flu virus has killed over 80 people and led to the destruction of millions of fowl 5 worldwide. The disease continues to spread.

There are several bird flu vaccines currently being developed, but researchers at the University of Pittsburgh have announced they have developed a vaccine that works on animals, and can be created quickly.

Swabing inside of mouth of bird   
  
Researchers used genes 6 from the bird flu virus and combined them with the common cold virus to create the vaccine. They then injected the vaccine in chickens. The chickens were later infected with avian flu, but none of them got sick.

Dr. Andrea Gambotto, with the University of Pittsburgh School of Medicine says the vaccine has tested 100 percent effective, "We have proven that this vaccine is 100% effective in both chickens and mice."

Their vaccine was genetically 7 engineered and was manufactured in only 36 days, as opposed to current flu vaccines, which take months to develop. The only drawback is that this new technology will not be widely available for several years.

Scientists, Dr. Gregory Poland with the Mayo Clinic believe it's an important step forward in fighting pandemics. "You can see the context of, an emergency of a pandemic, the importance of being able to produce a vaccine in weeks versus 8 months, the way we currently do it."

These potential vaccines hold promise for the future, according to Dr. Gary Nabel of the US National Institutes of Health.

"We're now moving forward with a lot of new approaches to flu. And the good news here is we've identified another one that appears to work."

The Pittsburgh researchers believe their vaccine will still be effective in protecting chickens even if the virus mutates.