Why are pandemics such dreaded events?

大流行病为什么如此可怕？

Only influenza a viruses can cause pandemics.

只有A型流感病毒可造成大流行。

Those were considered to be mild pandemics.

而这两次仅被视为轻度大流行。

Improving global preparedness for future pandemics.

加强全球对未来大流行的防范能力。

This phenomenon is distinctly seen during pandemics.

这是大流行期间常见的显著现象。