Srivastava, Hari M.Area Carracedo, Iván CarlosNieto Roig, Juan José2021-08-132021-08-132021Mathematical Biosciences and Engineering 2021, 18(4): 3274-3290. https://doi.org/10.3934/mbe.20211631547-1063http://hdl.handle.net/10347/26805In this work, power-series solutions of compartmental epidemiological models are used to provide alternate methods to solve the corresponding systems of nonlinear differential equations. A simple and classical SIR compartmental model is considered to reveal clearly the idea of our approach. Moreover, a SAIRP compartmental model is also analyzed by using the same methodology, previously applied to the COVID-19 pandemic. Numerical experiments are performed to show the accuracy of this approacheng© 2021 the Author(s), licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0)Atribución 4.0 Internacionalhttp://creativecommons.org/licenses/by/4.0/Compartmental epidemiological modelPower-series solutionCOVID-19Numerical approximationjournal article10.3934/mbe.20211631551-0018open access