Stop all the planes from flying all around the world carrying variants of all types all over the world. Its not much more complicated, but just consistently those in charge in most countries would rather shut everything else down then the damn planes. Some countries had enough sense to try to stop flights as first actions. The Airline industry much have a lot of pull with global govt. The Cruise industry got shut down just like that (right move) but the Airlines. they're allowed to fly pretty much undetered AND get more huge bail outs.
Lets just call the Country Air Canada and be done with it.