Has it ever broken out in a less humid climate? West Africa is wet. The virus stores well for research dried. Well, freeze-dried.
Freeze drying works but then it has to be sealed or it degrades with any residual moisture. Only some small portion reactivates if you humidify any freeze virus. I think freezing while wet works better for this virus if you want it active once you warm it back up.
The southeast USA, from D.C. to East Texas, is similar to West Africa, as far as humidity and temperature. Right there in N.C., the Great Dismal Swamp is pert-near jungle, and upstate the Smoky Mountains are one small notch short of a rain forest. North Carolina is wet AND sticky.
Don't you feel better now?