Figure 4.

The direct vaccination effort (σ) necessary for prophylaxis based on the cost of transgenesis and efficacy (ξ). Rows represent the $R_0^0$ of the vector used to create the vaccine and columns the $R_0^P$ of the pathogen targeted by the vaccine. The x-axis represents the fractional reduction in the transmission rate of the vaccine relative to the vector. A value of 1 on the x-axis reflects a non-transmissible live vaccine which is still vulnerable to mutation. The y-axis reflects the efficacy of the vaccine. For all parameter combinations, the mutation rate was constant (μ = 0.001). The blank regions in the two rightmost subplots define areas of parameter space where a pathogen of the given $R_0^P$ can always invade due to incomplete vaccine efficacy even if all individuals are directly vaccinated at birth.