I was a bookish kid. I spent long hours in the library reading everything I could find, histories, biographies, science fiction, fantasy, mysteries. … - Sanjay Gupta

When most people hear "flu," they typically think of . No doubt, seasonal flu can be deadly, especially for the very young and old, as well as those with compromised immune systems. For most people, however, the seasonal flu virus, which mutates just a little bit every year, is not particularly severe because our immune systems have already probably seen a similar flu virus and thus know how to fight it. It's called native immunity or protection, and almost all of us have some degree of it. Babies are more vulnerable because they haven't been exposed to the seasonal flu and older people because their immune systems may not be functioning as well. Pandemic flu is a different animal, and you should understand the difference.

flu is apolitical and does not discriminate between rich and poor. Geographical boundaries are meaningless, and it can circle the globe within hours. In terms of potential impact on mankind, the only thing that comes close is climate change. And, like climate change, pandemic flu is so vast, it can be challenging to wrap your head around it.

I was in my teens when our family faced a medical crisis. My grandfather, with whom I was very close, had a stroke and landed in the hospital. Sitting anxiously at his bedside, I watched nurses come and go, checking his vitals and looking at the monitors attached to his body. I remember sitting there wondering what could I do to make him feel better—to bring back the warm, thoughtful man I knew.