A curious but fortunate characteristic of virus epidemics is their limited life spans.  No one knows why, but guesses include herd immunity and mutations of the virus. The following graph from the Centers for Disease Control and the National Center for Health Statistics shows the time profile of the COVID-19 weekly death counts from February onward.  (For an interactive version of the graph, go here.) In the U.S., the virus got underway in March.  For the week ending March 14, the total number of deaths nationwide was 52.  During the following month, the number of deaths increased rapidly, peaking in the week ending April 18 at a count of 17,026. From that time onward, the death count declined rapidly to a weekly number of 3,684 in late June.  A second "wave" began in July.  The peak of that second wave was 6,794 deaths during the week ending July 25.  After that, a steeper decline...(Read Full Post)