The bulk of the chickens had to be killed because of the bird flu virus.

由于禽流感病毒，大部分的鸡都不得不被宰杀掉。

Meanwhile，China has approved a new type of flu drug that it believes may be effective in treating H7N9 bird flu virus.

同时，中国已批准可有效治疗H7N9禽流感的新型流感药物。

The H5N1 bird flu virus first appeared in 2003, it has killed more than half of the 622 people it has infected.

H5N1最初是2003年开始爆发，在622名感染者中，一半以上的人因此丧生。

Controversial research is set to resume on artificially creating a new highly contagious form of the H5N1 bird flu virus, which could be spread by humans. Rebecca Morelle reports.

科学家称将重启对一种新型高传染性H5N1禽流感病毒的研究，这种病毒可以通过人际传播，此举引起广泛争议。Rebecca Morelle报道。