Effect of Awareness, Quarantine and Vaccination as Control Strategies on COVID-19 with Co-Morbidity and Re-Infection

In this paper a deterministic compartmental model is presented to assess the impact of vaccination and non-pharmaceutical interventions (awareness, face mask and quarantine) on the transmission dynamics of COVID-19 with co-morbidity and re-infection. An expression for the basic reproduction number is then derived for this model. For the case of no re-infection, the model has a globally asymptotically stable disease free equilibrium (DFE) when the basic reproduction number is less than unity. Furthermore, in the case of no re-infection, a unique endemic equilibrium point (EEP) of the model exists which is globally asymptotically stable whenever the reproduction number is greater than unity. The model exhibits backward bifurcation phenomenon when the basic reproduction number is less than unity. Performing the global sensitivity and uncertainty analysis, we identify the parameters those have impact on the spread of COVID-19. Finally, optimal control analysis is accomplished by considering all combinations of the four control measures applied to our model to find which control strategy can play an important role to reduce the disease burden. Numerical simulations are performed to verify the theoretical results of the model and the simulation result shows that the use of effective vaccine could lead to the elimination of COVID-19 from the community. This study shows that by using an effective face mask and maintaining social distance, disease-related complexity can be lessened. The study also shows that the presence of any co-morbidity and occurrence of re-infection, increase the disease burden.Funding Information: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Declaration of Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.