The global features of a fractional-order general pathogen infection model with immune deficiency and two types of target cells are examined in this chapter. Both cell-to-cell and pathogen-to-cell transmissions are presented. We demonstrate that the system solutions are positivity and confined, Lyapunov function is considered to show global asymptotic stability for disease-free equilibrium point of the model. Analytical expression for basic reproduction number  and the required condition under which disease-free and chronic equilibrium points are asymptotically stable are determined. We carried out numerical simulations to utilize it to document the analytical results.