Flu:

Just a quick point:
Tamiflu isn't a vaccine. It's a drug that must be given at the onset of symptoms, nearly invalidating it's existance.

Let's say you start feeling the flu, you think. You decide to play it safe and rush on over to the hospital and see if it IS the flu. After hours and hours in the waiting room (You really think the flu is a high priority in the ER?), you see a doctor, who isn't really sure you have the flu. Let's say he decides to give you the Tamiflu: Did you get it in time?

As for me, I'll trust good old Vitamin C, thanks.