“…7 for some parameter values. To this end, the pair (R 0 , 1/c) is chosen (2.5, 5), (5, 5), (10, 5), (2.5, 10), (5, 10), (10, 10), (2.5, 20), (5,20), and (10,20), respectively, and the numerical evaluations for various infectious stages N are shown in Figure 10. It can be observed from this figure that the delay is almost half of the infectious period.…”