Have you ever wondered why is that only some people become sick when exposed to a pathogen? Why don?t all the members of a group from work get sick, when a colleague ? a sneezing, stuffy, coughing cold virus carrier, exposed them to the illness? Why don?t all the kids in your child?s classroom get sick, when it seems that just a few ?give the start? to the flu, all the time? It?s not about luck or the lack of it. It?s about how prepared your immune system is to fight with the pathogens. And this involves a very complex mechanism that takes place in your body daily, even from the day you were born!