A new crown antigen test for a cold will not result in a false positive in most cases, but the possibility of a false positive is not absolutely ruled out. Colds are a very common respiratory infection, and the pathogens are mostly rhinovirus, respiratory syncytial virus, echovirus, coxsackievirus, and to a lesser extent mycoplasma, chlamydia, and Haemophilus influenzae infections. The neocoronavirus antigen detects a component of the neocoronavirus and has a high sensitivity and specificity, but the possibility of false positives is not absolutely excluded. Such false positives generally occur when buffers are not used correctly, when there is a tolerance for antigen detection, and when the specimen is contaminated, and are associated with human immune dysfunction. If the new crown antigen test is positive, the diagnosis can be confirmed by a new crown nucleic acid test.