Figure 1.

Schematic diagram of the processes included in the mathematical model for the main system investigated, which does not consider backward mutations. The system is composed of two pathogenic strains: wild-type (variable z_w) and mutant (variable z_m) species, that compete for the infection of healthy cells (variable x, green cells). Infection of healthy cells gives rise to two different populations of infected cells with wt (variable y_w) and mutant (variable y_m) strains, displayed by red and blue cells, respectively. Viral strains are assumed to grow and mutate (dashed lines) within the cells, being released again to the system for further infection after cell lysis.