According to William Kemarck’s 1924 model contagion follows an S-shaped curve. The assumption was that those susceptible would become infected. Infect others, recover or die and go to heaven or hell, as in Christianity. In epidemiology, the reproduction number, or R , indicates how many new cases a single infected individual causes. If R is greater than 1, an outbreak grows. If it falls below 1, stops. Nobody goes to heaven or hell. R > 1: It...