\begin{array}{l} \begin{matrix} \begin{matrix} {\dot{H}}_{L} & = & (γ_{L} - α (s)) H_{L}, \\ {\dot{H}}_{R} & = & α (s) H_{L} - (δ_{R} (s) + d_{I} ({\bar{V}}_{I})) H_{R}, \\ \dot{N} & = & d_{L} H_{L} + (δ_{R} (s) + d_{I} ({\bar{V}}_{I})) H_{R} - μ N, \end{matrix} & \begin{matrix} \dot{L} & = & (γ_{L} - α (s)) L, \\ \dot{R} & = & α (s) L + (κ - q - δ_{R} (s) - d_{I} ({\bar{V}}_{I})) R, \\ {\dot{V}}_{I} & = & q R - (p + d_{I} ({\bar{V}}_{I}) + δ_{R} (s)) V_{I}, \end{matrix} \end{matrix} \end{array}