Ironically, it's in countries where there is partial vaccination that we haven't the greatest risk - partial pressure against the virus will select it for stronger ability to be vaccine resistant. It's why it's so important to give everyone two doses of vaccine as quickly as possible and vaccinate the entire population, so you don't have the virus spreading, mutating, and potentially evolving to become vaccine resistant and then endemic in the population. We only get one really good chance to hit herd immunity.

But - longer term - agree with you - wouldn't it be awesome if we had full-viral scans of travelers, international or otherwise - would shut down flu pandemics as well (most of them are imported from other countries).