Airborne

I just sampled a new herbal supplement to try to curb a cold. It's called Airborne. I haven't seen great results, as I am probably too far into the cold this time. What's interesting about the name of it, and true for me, is that I always seem to get a cold shortly after I fly. Why is this? Do planes really maintain higher concentrations of the virus? Wouldn't subways carry just as many germs?

Perhaps it also has something to do with my trying to fit in one too many activities during my travels (and sleeping too little). Then again, that is not so different from my everyday life.