​Recently, many nonlinear systems have been proposed to intro-duce the population dynamics of COVID-19. In this paper, we extenddifferent physical conditions of the growth by employing fractionalcalculus. We propose a new fractional-order version for one of re-cently forms of the SEIR model. This version, which is establishedin view of the Caputo fractional-order differential operator, is numer-ically solved based on the Generalized Euler Method (GEM). Severalnumerical results reveal the impact of the fractional-order values onthe established disease model. To help make a decline in the total ofindividuals infected by such pandemic, a new compartment is addedto the proposed model; namely, the disease prevention compartmentthat includes the use of face masks, gloves and sterilizers. In view ofsuch modification, it turned out that the performed addition to thefractional-order COVID-19 model yields a significant improvement inreducing the risk of COVID-19 spread.