Recent studies affirmatively revealed that infectious cases of the virus are not restricted to asymptomatic and symptomatic. There is an infectious class – the presymptomatic infectious individuals, a non-trivial infectious case which has posed more threat to humanity. These individuals’ symptoms are delayed due to their intermediate immune system and then become a threat to the population after 21 days of the incubation period. In this study, we proposed 7-dimensional nonlinear ordinary differential equations of the form SEIsIaIpTR which incorporate the presymptomatic infectious individuals and then considered the effect of infectivity factors on all forms of infectious status to emphasize the presymptomatic individuals cannot be ignored in the treatment of infected individuals. The non-negativity and boundedness of the dynamical system were at all-time proved to be true. Also, the endemic and disease-free points of equilibrium were detremined to be locally and globally asymptotically stabled. The dynamical behaviors are succinctly conducted with the use of MATLAB.