In this article, we predict the required vaccine coverage to eradicate the COVID-19 outbreak in Sierra Leone. We also, investigate the impact of facemask and vaccine coverage on the spread of the COVID-19 virus using a modified symptomatic-asymptomatic infection transmissions Susceptible-Latent-Infectious-Asymptomatic-Recovered (SLIAR) model. We derived an explicit formula for the basic reproduction number and used it to understand the dynamics of the disease when it is greater than unity. Numerically, we show that 58 per cent of the Sierra Leone national population required vaccination to eradicate the COVID-19 virus. Also, the SLIAR with vaccine model results reveal that the impact of using facemask is very challenging to understand and the vaccine coverage decrease the infected transmission rate but cannot completely eradicate the infection.