Early in March 2020, I decided to write about the risks posed by COVID-19. I have no background in epidemiology or even health journalism, but I can multiply, divide and make charts, and was frustrated with the lack of quantification in most reporting and public health messaging on what was soon to be declared a pandemic. In the resulting column, I took what seemed to be the most authoritative estimate of COVID’s per-infection fatality rate – 1% – and noted that this was about 10 times the 0.1% fatality rate of seasonal influenza, then conservatively multiplied a Centers for Disease...