The emergence of a coronavirus disease (COVID-19) pandemic caused by severe acute respiratorysyndrome coronavirus 2 (SARS-COV 2) has caused an unprecedented global societal andpublic health crisis. A novel variable (genetically resistant humans, which they serve as reservoirhost) that could influence the prevalence of COVID-19 pandemic have been incorporatedand analyzed rigorously. Detection and testing for COVID-19 (in humans that are geneticallyresistant to COVID-19), proper preventive measures, and timely medical care are essential inmanaging and controlling COVID-19 outbreak. First, we analyze the disease-free state of theCOVID-19 model, calculate the baseline control reproduction number, and obtain the localstability of disease-free equilibrium. The model is calibrated using data obtained from NigeriaCentre for Disease Control and key parameters of the model are estimated. Sensitivity analysisis carried out to investigate the influence of the parameters in curtailing the disease. Numericalsimulations are then used to explore the behaviour of the model solutions involving the novelvariable (genetically resistant humans) and control measures. Our results suggest that strictintervention effort (early detection of genetically resistant individuals, testing and isolation ofthe infected individuals) is required for quick suppression of the disease.