They just have to give everyone face masks and a few sets of disposable gloves. Keep them on at all times except for eating. Maybe stagger the meal service on longer flights over a longer period of time so everyone's mask isn't off at the same time. Have lots of wet wipes/clorox wipes available.

For mass transit it will be about reducing risk as much as possible without bankrupting the provider (in this case, airlines). You take your chances if you fly. It's going to be this way anyway for the next 18 months or so after shelter in place restrictions are gradually lifted. Those most at risk will have to be more cautious. The rest of us will have to do what we can while at the same time allowing some sort of normality to return.

This disease is highly infectious and contagious, so the shelter in place precautions at the moment are saving lives. If it was left to run rampant we'd have bodies piled up more than we have already. The comment a few up about the death rate from flu being the same just isn't an accurate statement at this time. If we let it go, a lot more people would have died vs the common seasonal flu.