Nucleic acid test should not be done immediately after vaccination, mainly because the residual nucleic acid fragments and vaccine contamination will affect the accuracy of the test results and may cause false positives. 1. Nucleic acid fragments: Generally, inactivated vaccines need to be cultured and inactivated, etc. Although the virus loses its activity and cannot cause the body to be infected and cause disease, there are still nucleic acid fragments, which can easily lead to false-positive test results and interfere with the order of nucleic acid test. 2. Vaccine contamination: In the process of vaccination, the staff need to take the vaccine extraction and exhaust, which may lead to vaccine contamination, and then lead to the vaccine containing viral nucleic acid sequences in the nose or throat of the vaccine recipient, which may easily affect the results of nucleic acid testing. It is recommended that new vaccine recipients should wait 48 hours before taking the nucleic acid test.