If the first time is negative, the chances of a positive retest are not great, but there is still some chance of a positive retest. If it was positive the first time, there is a higher chance that the nucleic acid will retest positive. If there is a history of sojourn or contact with people in a high-risk area, that is a high-risk group, and multiple nucleic acids are usually done in order to rule out whether or not they are infected with the new crown. 1. Most people who are negative the first time have a very small chance of being positive if they are retested, but there is still a certain chance of being positive. For example, if the patient is in the incubation period or samples containing the new crown virus were not collected during sampling, it is possible that the retest is still negative but the patient is actually infected with the new crown virus. 2. If the first nucleic acid test is positive and the patient has a history of living in a high-risk area or having close or sub-closely connected infections, there is a high probability of a positive retest. Usually, several rounds of review are needed to confirm the diagnosis of C.neoformans pneumonia. One round of positive nucleic acid is not enough to diagnose C.neoformans infection, and it is also necessary to combine the patient’s clinical manifestations, respiratory function assessment, and imaging examinations to make a comprehensive judgment. During the new crown epidemic, avoid going to crowded places, pay attention to personal hygiene, go out to take protective measures, wear a good mask, and receive the new crown vaccine to reduce the risk of infection. Tips] In this article, “new coronavirus pneumonia” and “new coronavirus pneumonia” have been renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.