Back in the day when I was in the lab and this hand sanitizing thing took off, the company I worked for wanted in on the action. In studies, good-old hand washing was just as good, and in some cases better, than sanitizing with alcohol-based sanitizers. This was against bacteria. Virus's are a whole different story though. Alcohol works against some the enveloped ones (Corona, Influenza), but doesn't do shit against un-enveloped virus's like Coxsackie, Rota, Noro and Rhino. Bottom line is wash your hands thoroughly when you get to where you're going, and until then keep them away from your face, and when you eat out try to eat cooked, not raw foods. All of this reduces your chances, but nothing will ever reduce them 100%.