Updated: Mar 27, 2020
We now know that the virus that causes COVID-19 can be spread through air or touch anywhere, even from people who have no symptoms, and by inanimate surfaces like plastic and metal for as long as 2-3 days. That's why social distancing, frequent hand washing, and surface disinfecting are so important. Everyone should stay at home as much as possible until the worst of this passes.
There is an eye-opening report in the 3/13/20 issue of Science documenting that airport screening is largely futile. It says that "thermometer guns and health questionnaires may look reassuring, but very rarely catch infected travelers." It may actually be doing much more harm than good to delay passengers in long, crowded lines that greatly facilitate rather than prevent the spread of the virus.Contrary to big pronouncements by non-scientists, drugs and vaccines of proven effectiveness are months away at best, so behavior change is the only defense we have at this critical stage now.