To that nagging question, the answer increasingly seems to be yes. Certainly, they were a novelty. As novelist Lionel Shriver writes, "We've never before responded to a contagion by closing down whole countries." As I noted in May, the 1957-58 Asian flu killed between 70,000 and 116,000 Americans, between 0.04% and 0.07% of the nation's population. The 1968-70 Hong Kong flu killed about 100,000, 0.05% of the population. The U.S. coronavirus death toll of 186,000 is 0.055% of the current population. It will go higher, but it's about the same magnitude as those two flus, and it has been less...