Of all these, mass testing deserves special emphasis, because without it any emergency response is all but hamstrung. A nation cannot fight an epidemic without knowing where the disease actually is.
The best-performing countries, however, excelled on all three levels. Taiwan has a Medicare-style single-payer system (indeed, it was actually based initially on America’s Medicare system, except made universal), which allowed them to deploy testing, treatment, and quarantine without any fuss. They also had pandemic response plans drawn up after the SARS outbreak in 2002, which had been regularly reviewed and practiced. Finally, their citizens had been educated and prepared to take any epidemic seriously, so that people did not try to escape lockdowns and spread the disease further.
Even middle-income countries can manage this. Vietnam, whose per-capita GDP was only about $6,600 in 2018 (or about 12 percent as much as the U.S.), squelched its initial epidemic with a lightning-fast deployment of mass testing, contact-tracking, quarantine, and public education measures (though it has since been dealing with new infections from foreign travelers). If the state is on top of the situation, mass lockdowns and the associated economic devastation can be limited or avoided.