Wired:

The world is not going to begin to look normal until three things have happened. One, we figure out whether the distribution of this virus looks like an iceberg, which is one-seventh above the water, or a pyramid, where we see everything. If we’re only seeing right now one-seventh of the actual disease because we’re not testing enough, and we’re just blind to it, then we’re in a world of hurt. Two, we have a treatment that works, a vaccine or antiviral. And three, maybe most important, we begin to see large numbers of people—in particular nurses, home health care providers, doctors, policemen, firemen, and teachers who have had the disease—are immune, and we have tested them to know that they are not infectious any longer. And we have a system that identifies them, either a concert wristband or a card with their photograph and some kind of a stamp on it. Then we can be comfortable sending our children back to school, because we know the teacher is not infectious.