Nucleic acid refers to the nucleic acid test, which can be done 48 hours after the new Crown vaccine. The substance in the nucleic acid test is the nucleic acid of the virus, and by doing the nucleic acid test, you can determine whether or not the virus is present in the person being tested. If the test is done within 48 hours of the vaccination, the test should not be done to avoid false positives, but can be done after 48 hours without affecting the test result. If the nucleic acid test result is positive, it indicates that the virus is present in the body, and you need to go to the hospital in time. If the nucleic acid test result is negative, it means that the virus has not been detected in the body, but the virus may have a certain incubation period in the body, so it is recommended to do the nucleic acid test several times if there is a high prevalence of the virus or if there is direct or close contact with people infected with the virus.