I don't think borders matter much, or closing airports now. All that guff is just gesture stuff. What matters now is testing for Corvid 19, identifying and isolating vulnerable groups, spending hugely more on your Health Service (or establishing one if you still live in barbarism) and making sure you have the proper equipment, particularly ventilators.
Closing the borders is almost literally closing the barn door after all the horses have gotten out. It is here right now, so trying to stop it from coming is pointless.
The test is soon losing its point. The disease is almost certainly growing out of control. Testing and quarantining time has not completely past, but it is passing.
Vaccines are at least a year away. A reasonable cure is decades away.
The reality is we are locked into whatever will happen. We might have some time to get a few more ventilators, but even the chances for that are passing.