Ndlovu, MeshachMoyo, RodwellMpofu, Mqhelewenkosi2022-10-262022-10-262022-05-25https://doi.org/10.1016/j.pce.2022.103167http://ir.gsu.ac.zw:8080/xmlui/handle/123456789/65This paper presents evidence and the existence of seasonality in current existing COVID-19 datasets for three different countries namely Zimbabwe, South Africa, and Botswana. Therefore, we modified the SVIR model through factoring in the seasonality effect by incorporating moving averages and signal processing techniques to the disease transmission rate. The simulation results strongly established the existence of seasonality in COVID-19 dynamics with a correlation of 0.746 between models with seasonality effect at 0.001 significance level. Finally, the model was used to predict the magnitude and occurrence of the fourth wave.enCOVID-19, Seasonality effect, Mathematical modelling, Dynamics, Environmental factors, ZimbabweArticle