Researchers hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later.

研究人员推测，这种疫苗就是几十年后在间皮瘤中发现的病毒的来源。

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Today, we know that a virus with great pandemic potential, the new strain of the H1N1 virus, has emerged from another source on another side of the world.

今天，我们知道一种具有大流行强大潜力的病毒，即H1N1病毒的新毒株，从世界上另一边的另一个来源产生。

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Investigations of human cases in Asia and elsewhere have identified close contact with diseased or dead household poultry as the most important source of human exposure to the virus.

在亚洲和其它地方对人间病例的调查已确认与家庭禽群或死禽直接接触为人与该病毒最重要的接触源。

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And so in the 1940s, a group of people led by Collier started to develop a large scale production method for making a reliable source of vaccinia virus.

在二十世纪四十年代,科利尔带领一群人开始研究,一种大规模的生产方法,这种方法能制得牛痘病毒的可靠来源

耶鲁公开课 - 生物医学工程探索课程节选

While the source of the virus remains unknown, further surveillance will help in understanding its transmission, said Liang Wannian, director general of the health emergency division of China's National Health and Family Planning Commission.

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Diosdado Nsue-Micawg, the WHO representative in the Angolan capital of Luanda, said the health agency does not know the source of the virus, but fears that hunters and women who visit the forest might have been in contact with infected monkeys.

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Scientists are still trying to figure out the source of the new virus.

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