Abstract
In this article, the Caputo fractional derivative operator of di fferent orders 0 < alpha <= 1 is applied to formulate the fractional-order model of the COVID-19 pandemic. The existence and boundedness of the solutions of the model are investigated by using the Gronwall-Bellman inequality. Further, the uniqueness of the model solutions is established by using the fixed-point theory. The Laplace Adomian decomposition method is used to obtain an approximate solution of the nonlinear system of fractional-order di fferential equations of the model with a different fractional-order alpha for every compartment in the model. Finally, graphical presentations are presented to show the e ffects of other fractional parameters alpha on the obtained approximate solutions.