Analysis of mathematical model involving nonlinear systems of Caputo–Fabrizio fractional differential equation

In this paper, we consider a mathematical model of a coronavirus disease involving the Caputo–Fabrizio fractional derivative by dividing the total population into the susceptible population [Formula: see text] , the vaccinated population [Formula: see text] , the infected population [Formula: see text] , the recovered population [Formula: see text] , and the death class [Formula: see text] . A core goal of this study is the analysis of the solution of a proposed mathematical model involving nonlinear systems of Caputo–Fabrizio fractional differential equations. With the help of Lipschitz hypotheses, we have built sufficient conditions and inequalities to analyze the solutions to the model. Eventually, we analyze the solution for the formed mathematical model by employing Krasnoselskii’s fixed point theorem, Schauder’s fixed point theorem, the Banach contraction principle, and Ulam–Hyers stability theorem.