Figure 1.

Simulated profiles of epidemic growth (a) and corresponding effective reproduction number (b) based on the generalized-growth model during the first five disease generation intervals. The parameter p is varied from 0.2 to 1.0, whereas the growth rate parameter r is fixed at 0.65 per day and C₀ = 1. The length of the generation interval is assumed to be fixed at T_g = 3 days. When p = 1 (exponential growth), the reproduction number is constant at . When p < 1 (subexponential growth) the reproduction number gradually declines over time and approaches 1.0 asymptotically. The black circles correspond to calculated using the analytical formula in equation (2.6), whereas the solid lines correspond to the estimates from numerical solutions based on renewal equation (2.7). (Online version in colour.)