Asian Journal of Pure and Applied Mathematics

This research study aims to estimate and analysis the transmission rate, progression rate, recovery rate, death rate and the basic reproduction number for the Nigeria COVID-19 cases using the non-linear least-squares method. The disease-dynamics is described by susceptible – exposed – infected – recovered (SEIR) epidemic model using the non-linear ODEs. The disease eradication threshold is derived from the reproduction number ^R₀ , where ^{R_{0 =} 2.201866}. The estimated parameters are used to model the disease outbreak’s possible trajectories. The computed R-squared for the curve-fit is 0.97 and the error of our model estimate, for the first 62 days, is between 0 and 0.000001. These results point to the reliability and accuracy of the model estimates. Our result further shows that the peak day of the spread of the virus will be 155^th day from the start of the outbreak of the infection with about 13,981,546 infected. The observed death case is very minimal, though the number of infected persons is high. The computed immunity rate show that very small (negligible) numbers of recovered persons become susceptible again. Our numerical results shows that administration of covid-19 vaccine with 50% or above effectiveness will reduce the product rates of transmission and progression compared to the social distancing order.