The reason why nucleic acid should not be done 48 hours after the vaccine is that the vaccine may affect the nucleic acid results, resulting in false positives. New crown vaccine is mainly prepared by the new crown virus through inactivation, culture and other processes, after injection into the human body can make people produce antibodies, and at this time if the nucleic acid test will have an impact on the results. At the same time, after vaccination, we should pay attention to rest, avoid smoking and alcohol, do not exercise strenuously. In addition, do not eat seafood and other easily allergic food, may affect the efficacy of the new crown vaccine. In daily life, pay attention to develop good habits, go out and wear a mask, do not go to crowded occasions, so as to avoid cross-infection, at the same time pay attention to diet, appropriate exercise, in order to improve the body’s immunity.