The global outbreak of coronavirus disease-2019 (COVID-19) has affected most countries in the world. Our knowledge of diagnostic tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is evolving, and it is important to have a clear understanding of the nature of the tests and the interpretation of their findings. In this paper, the purpose is to interpret the results of two types of diagnostic tests commonly used for SARS-CoV-2 infection. Antibody testing is frequently positive after the occurrence of initial symptoms and generally during the following 10 days, and 80% of patients will have antibodies in their serum ten days after the onset of clinical symptoms. Serological tests with appropriate sensitivity and specificity are essential for rapid quarantine and timely treatment of patients; in fact, they can identify a large number of patients with mild symptoms and asymptomatic carriers. Based on information obtained from other known infectious diseases, it is possible that infected individuals may have at least some short-term immunity to COVID-19. As governments plan to remove the restrictive measures applied for overcoming COVID-19, one of the proposed programs is to give people who have recovered from COVID-19 an immunity passport or a digital safety certificate. In fact, such certificates indicate that the individuals are safe and harmless and they no longer spread the disease.