Stability when . Panel (a) shows the scenario with no vaccination, whereas panel (b) shows the scenario with 100% child and 100% adult vaccination. The dashed line represents , and the solid line represents . These are the two conditions that determine the stability of the disease-free equilibrium for our system. The disease-free equilibrium is stable in the region where the dashed line is above the solid line and when the solid line is above zero. This region is shown in more detail in the inset graph. We compare these conditions to since these parameters always show up in this fashion. The values indicated in the inset graphs are the critical values which determine when the disease-free equilibrium becomes unstable. Since panel (a) includes no vaccination, this indicates that the actual value of within the Canadian population must be at least 1.02 since HPV is an epidemic and has not been eradicated. Since panel (b) depicts the scenario with 100% childhood and 100% adult vaccination, if the actual exceeds 2.95, then, even with 100% vaccination, we cannot eradicate HPV.