Well, it's just a few days to the start of NRF, and the nation is in the grip of a flu epidemic. Taking a quick peek at the CDC (Center for Disease Control) maps, you can see that the epidemic is widespread in almost all of the United States.
What can you do ? Speaking only for myself - as someone who doesn't want to get sick from that or the norovirus, or pertussis that is sweeping the nation too - here are some ideas;
A) If you're sick - don't come.
B) Be sure to cough or sneeze into your arm.
C) Wash your hands. Again and again.
D) Refrain from shaking hands.
E) Keep some antiseptic waterless gel in your pocket for disinfecting your hands. You can get a small pocket size container for a buck or two just about anywhere.
Need more motivation? Read this article in the NY Times about Widespread Flu. If you're coming to NRF, just remember that out of 25,000 attendees, it's statistically likely some people will be carrying it. :(