The diagnostic sensitivity is 97.56 % (ct value: 20 – 30), and the diagnostic specificity is >99.9 %. That means that positive results from antigen tests are very precise. However, as there is always a residual risk of a false-negative result, when in doubt, a PCR test should be carried out to confirm negative results. The choice between antibody, antigen and PCR tests is not an either/or decision. Rather, the best tactic is a combined application.