In this article, the nonlinear SICQR model explains the dynamics of transmission of infectious diseases in a community. This model has five epidemiological compartments: susceptible S, infective I, individuals with strong immunity C, quarantined Q and recovered R. The desired model owns different equilibrium cases as an endemic equilibrium and a disease free equilibrium. This model describes the importance of strong immunity for community members to control the spread of COVID-19. The shifted Chebyshev spectral collocation (SCSC) technique is utilized to find the numerical solutions the desired model. The obtained results clarify the influence of strengthening the immunity of community members on controlling the spread of the disease.