[CryptoPunk]

>>The goal is to maintain measures until a vaccine arrives, eliminating the threat for any said country.

Yes of course, but if the crop of vaccines prove, after more extensive usage, ineffective, or if the virus mutates quickly enough to make the currently developed vaccines ineffective, as many coronaviruses have been known to do, it may lead to indefinite on-off lockdowns.

>You don't need the country to be isolated from the rest of the world. If the effective reproduction (R) of your country's population is below 1 it won't spread there, even if the rest of the world is letting it run wild and free.

That only persists as long as the lockdown measures you mentioned are in place. Yes if you maintain those measures indefinitely, you can keep the virus at bay indefinitely, and that's a different claim than I thought you were initially making.