I would say that the masks are certainly helpful, but I really like to think of this as a bundled approach. The use of masks, distancing when possible, the ventilation system on the plane and hand hygiene are really parts of a bundled approach.
It's hard when you start teasing it apart and saying, “Well, I can eliminate this, but I'm going to keep that.” I think it starts to fall apart. If we just keep it bundled together, we'll be as safe as possible.