Influenza does not rate with the public as a terrifying disease. One might start a panic any time by shouting “smallpox!” or “yellow fever!” in a crowd, but can you picture any considerable number of people running from “the flu”? The term has a frivolous, almost comical connotation, quite in contrast with the fearsome images invoked by such portentous words as “Asiatic cholera,” “typhus,” and “plague.” It would be mere posturing to belittle the history of these scourges, but one may fairly question whether in the long roll of the centuries any of them outranks epidemic influenza as a…