Numerical Simulation for a Hybrid Variable-Order Multi-Vaccination COVID-19 Mathematical Model

In this paper, a hybrid variable-order mathematical model for multi-vaccination COVID-19 is analyzed. The derivative defined as linear combination of the integral Riemann–Liouville and Caputo derivative. A symmetry parameter ? presented in order to be consistent with physical problem. existence, uniqueness, boundedness positivity proposed are given. Moreover, stability discussed. theta finite difference method discretization operator developed solving numerically This can explicit or fully implicit large region depending on values factor ?. convergence analysis proved. fourth generalized Runge–Kutta also used study model. Comparative studies numerical examples presented. We found that more general than previous study; results obtained by stable research area.