Getting sick can feel like bad luck. Symptoms, such as a sore throat, runny nose, headaches, and cough seem to descend out of nowhere just to make us miserable. This misery can drag on for a week or more, forcing us to take time off or work through an illness.
However, infections are not due to luck, but microbial pathogens. We all confront numerous illness-causing pathogens everyday—an ever changing mix of flu and respiratory viruses found in the air we breathe and the surfaces we touch. But why do some people seem to stay symptom-free, while others are constantly reaching for the Kleenex?