[LinuxBender]

Masks don't cover eyeballs and hands. Plenty of scientists have learned the hard way what happens when you don't wear proper eye protection and work with viral material. Rabies is especially not forgiving. There are plenty of other ways to get a virus into the system. Micro-fractures in the nasal passage, gum disease, open wounds. Shaking hands then rubbing your eyes or picking your nose. I could go on and on, but this would get really graphic.