Figure 4
From: Time variations in the transmissibility of pandemic influenza in Prussia, Germany, from 1918–19
Comparison of the effective reproduction number assuming different serial intervals. Expected values of the effective reproduction number with a serial interval of 1 (grey), 3 (dashed black) and 5 days (solid black). The horizontal solid line represents the threshold value, R = 1, below which the epidemic will decline to extinction. Days are counted from September 9, 1918, onwards.