A rhinovirus is one that most of us are very familiar with: the viruses that are responsible for the common cold. They are also the most common viral infective agents that attack the human body, with around ninety-nine recognized types. They spread mostly by airborne particles (someone sneezes next to you) or contaminated surfaces (you open a door an infected person has touched—and in particular, you then rub your eyes or nose, where the virus is easily picked up by your mucus membranes). And this virus is fast—sticking to surface receptors within fifteen minutes after it enters your respiratory tract.