How to boost the immune system during frequent travel?
Over the last year or so I have been traveling extensively and many of my long-haul trips have ended in illness. I've fallen ill in Argentina, Russia, France and now the U.K. I have almost never been sick in the last decade when staying at home or traveling less frequently. Most of the travel has been long-haul intercontinental flights. Are there any supplements you guys recommend to stay healthy while aloft and out and about?