The book does a great job of expressing the history of medicine leading up to the 1918 Spanish Flu.
But above all the book goes into detailed recollection on the arrogance of leadership in the face of this deadly disease. From politicians listing it as merely a regular flu, to military generals choosing not to quarantine troops... leading to massive casualties and the spread of the disease. All leading up to a realization of severity, when proper measures are taken.
I believe a newer print also has a note about Swine Flu, my copy is fairly old and does not include this.