The storage conditions are not unknown. There is documentation on every lot to guarantee that they were stored in the proper conditions and to evaluate how they should be stored going forwards.

There is also no reason to fly to these locations. There is already the logistic capacity to ship in the proper conditions between these locations and a few central hubs. It just has to be run in reverse. It hasn't been done for hundreds of locations because few countries are as big as the US, but it has been done on a smaller scale by less capable actors.

> There is already the logistic capacity to ship in the proper conditions between these locations and a few central hubs. It just has to be run in reverse.

You can't just duplicate existing routes. The logistics to collect unused vaccines from endpoints (on an insanely tight clock), would be enormously complex. We'd be setting that up on a nationwide scale, in the middle of a worldwide transportation shortage.

Further increasing exportable vaccine production would seem to be a more attainable goal.