If a new crown vaccine is administered, a nucleic acid test within 48 hours can affect the nucleic acid test results. The inactivated virus vaccine contains the nucleic acid sequence of the virus, and during the process of administering the New Crown vaccine, the vaccine may contaminate the place of vaccination, the vaccinators, and the vaccinees directly or indirectly in the form of liquid or aerosol through operations such as extracting the vaccine and venting the syringes, thus leading to the presence of the nucleic acid fragment of the New Crown virus in the nasal cavity or the mucous membranes of the throat of the vaccinees, and when detecting the New Crown nucleic acid of the nasopharyngeal secretion, the False-positive results can occur. When tested after 48 hours, the neocoronavirus nucleic acid fragments can be excreted with the nasopharyngeal secretions, and the residual nucleic acid fragments will be greatly reduced, reducing the possibility of false positives.