How did New Zealand stamp out coronavirus?

New Zealand lifted most of its coronavirus restrictions on Monday as the country reported no active cases. Prime minister Jacinda Ardern said she "did a little dance" when she was told the country was effectively coronavirus-free, meaning all of New Zealand was to be moved to level 1, the lowest of a four-tier alert system, with the goal of completely ending transmission of Covid-19 within its borders. Under the new rules, which come into effect at midnight local time on Monday, people no longer need to social distance from each other and there are no limits to public gatherings but, crucially, borders remain closed to foreign travellers. Today we can announce that there are now no active...