TABLE 1.

Summary of parameters used in our model.

Parameter	Model function
$b$	Birth rate
$\mu$	Host mortality rate
$\gamma$	Density-dependent population regulation
$q_i$	Strength of general resistance
$r$	Strength of specific resistance
$c_r$	Cost of specific resistance
$c_q$	Cost of general resistance, proportional to $q_i$
${\beta }_{\mathrm{e}}$	Transmission rate of endemic pathogen
${\beta }_{\mathrm{f}}$	Transmission rate of a foreign pathogen
$\theta$	Curvature of general resistance cost function