(a) Normalized mean times to fusion and endocytosis plotted as functions of kf/p1, the fusion rate per coreceptor-spike complex. Parameters used were M = N = 100, q1/p1 = 50, ke/p1 = 0.001. (b) Normalized mean times to fusion and endocytosis plotted as functions of ke/p1. Here, M = N = 100, q1/p1 = 5, and kf/p1 = 10−6, were used. For reference, Qe, the corresponding probability that the virus undergoes endocytosis is also plotted.