"... not because I think it has found the magic balance — it is way too soon to tell — but because I think we should be debating all the different ways and costs of acquiring immunity. When I look across America, though, and see governors partly lifting lockdowns — because they feel their people just can’t take it anymore for economic or psychological reasons, even though their populations have little or no immunity — I worry we may end up developing more herd immunity but in a painful, deadly, costly, uncoordinated way that still leaves room for the coronavirus to strike hard again and overwhelm hospitals.... Herd immunity 'has historically been nature’s way of ending pandemics,' added Dr. David Katz, the public health physician.... 'We need to bend with her forces...' That means a designed strategy, based on risk profiles, of phasing back to work those least vulnerable, so we gradually cultivate the protection of herd immunity — 'while concentrating our health services and social services on protecting those most vulnerable' until we can sound the all-clear."
From "Is Sweden Doing It Right?/The Swedes aren’t battling the coronavirus with broad lockdowns" by Thomas Friedman (in the NYT).