I recently ran across How Your Brain Prevents You From Getting Sick on Medium.
In synopsis, your subconscious directs your behavoir, steering you away from danger in every waking moment, if you let it.
I've also seen the results of experiments that compare how inhaling a virus vs. touching a virus then your face cause infection. Surprisingly, contracting a virus by touching your face is vastly less likely than inhaling a virus. Washing your hands is probably a good thing, but staying away from infected air is far more imperitive. Futhermore, if you let it, your subconsious will guide you to do the right thing - that is if you believe infected air is something to avoid. Otherwise, all bets are off.
There are so many things about ourselves we don't understand. It is clear however, that remaining level headed is more important than ever.