Epidemien - SIR model without vital dynamics

Blue: Susceptible population rate
Red: Infected population rate
Green: Recovered population rate (which means: immune, isolated or dead)

Hong Kong flu: initially 7.9 million people, 10 infected, 0 recovered. Thus S(0) = 1, I(0) = 1.27E-6, R(0) = 0, see http://www.cs.princeton.edu/introcs/94diffeq/.