The most fundamental thing to understand about serious pandemic influenza is that, except at a molecular level, the disease bears little resemblance to the flu that we all get at some time.

• 要了解危险的全球流感，除了要知道它的分子生物学之外，最重要的知道就是它和我们偶尔罹患的流行感冒有很大的差异。