There is no problem in general if you have a mild cold, but it may affect the monitoring of adverse reactions to the vaccine and aggravate the symptoms of the cold. 1, affect the monitoring of adverse reactions to the vaccine: because a mild cold is manifested by symptoms such as nasal congestion, runny nose, sore throat, weakness, cough, coughing, sore limbs or with low fever, etc., while the adverse reactions to the vaccination with the new crown vaccine mainly include weakness, drowsiness, fever, sore throat, etc., some of which are easily confused. Some of the symptoms are easy to confuse, and failure to deal with them in time may lead to serious consequences once adverse reactions to the vaccine occur; 2. Aggravation of cold symptoms: The immunity of the human body decreases when there is a slight cold, which may lead to a more likely occurrence of adverse reactions after vaccination with the new crown vaccine or aggravate the degree of adverse reactions, and some patients may also experience aggravation of cold symptoms. However, even if you have a mild cold, you should not be too nervous after receiving the new crown vaccine. After vaccination, for patients who only have symptoms such as axillary body temperature <37.3℃, mild nasal congestion and runny nose, there is no need to worry about other obvious discomfort symptoms, so you can observe more and seek medical consultation promptly if the discomfort symptoms worsen.