Half-measures are often far less than half-as-effective. Mini-lockdown didn't work because it wasn't a real quarantine, isolation was not achieved. Did you know the word quarantine comes from Latin meaning forty days? Because that's how long ships were kept out of Venice in the late 1300s to make sure nobody on board had the plague. That's the kind of harsh policy required for success, but the world decided that the immediate economy is worth more than permanent eradication of dangerous pathogens.