You cannot stamp out the virus; you have to let it run its course.
Like the earlier SARS, it has run its course when there are no new infections - and I’m sure New Zealand is looking at the economic chaos this has caused in the US and wants to head it off.
Americans don’t seem to understand how long-term the economic consequences of this will impact us going forward; the death toll is only one part of the story. Many small businesses are finished, and many large ones (retailers) are as well. Consumer confidence is in the toilet for most people worried about their jobs (as they watch their employers suffer).