The ships plying global sea trade started spreading plague epidemics no later than the 1500s. (Not to mention colonization, or Columbus.) War made the so-called Spanish flu widespread. We're not sure yet whether that one started in Kansas.
Both moved a lot slower than today's airplanes. They've become the disease's vector of choice ... and hugely bear the responsibility for accelerating regional epidemics into global ones.
How long did it take to shut down air travel once Wuhan happened? Why is that? Taiwan was expected to be badly hit. Take a close look at Taiwan's route to success. https://jamanetwork.com/journals/jama/fullarticle/2762689