We are not seeing the factors that were associated with other H1N1 viruses, " Besser said.

我们没有看到和其他H1N1型流感病毒有关的因素。

youdao

Dr Besser said more information was needed to determine the extent of the threat posed by the virus.

贝丝医生说，还需要更多信息来确定此病毒引发的威胁的程度。

youdao

To be declared a pandemic, Besser said, the virus must be new, cause severe disease, and transmit easily enough to be sustained.

贝瑟说，只有病毒是新型病毒，病情严重，其传播速度保持在较快水平上，才能宣布为进入爆发流行状态。

youdao

The acting director of the U.S.Centers for Disease Control, Richard Besser, spoke on ABC's "This Week" program.

VOA: standard.2009.05.03

But the interim director of the U.S.Centers for Disease Control and Prevention, Richard Besser, says it will be months before any decisions are made about mass-inoculations.

VOA: standard.2009.04.30

President Obama said Sebelius is watching the situation carefully, along with Homeland Security Secretary Janet Napolitano and Dr.Richard Besser, the acting Director of the U.S.Centers for Disease Control and Prevention.

VOA: standard.2009.05.01

"The virus continues to spread, both domestically and around the world, " said Richard Besser, the acting CDC director.

CNN: Mexico lowers swine flu alert as businesses in capital reopen

Dr. Richard Besser, the CDC's acting director, said that closing schools in a pandemic has a definite benefit.

CNN: Second U.S. death linked to swine flu, officials say

Dr Besser said more information was needed to determine the extent of the threat posed by the virus.

BBC: Experts probe deadly Mexico flu