Coronavirus
Herd immunity is one way to approach it. But only if the spread is manageable, i.e. less than 1:1. Then, yes, we potentially get better overall immunity and buy time like you said. But you need to hammer it first to get to that stage as per "The hammer and the dance" article that
@Andrew M put up. So, initially the idea is to smash it with extreme social distancing and quarantining measures, and yes, shutting everything down. And then gradually lay off until you're at a low level that's controllable. Short term economic hurt for long-term economic sustainability.