Usually before vaccination, it is necessary to assess whether the patient is in the contraindicated range of the vaccine, and it is also necessary to note that some vaccines cannot be mixed or given at the same time, and the patient needs to explain the situation to the doctor to determine whether the vaccination conditions are met. Usually the following points need to be noted before vaccination: 1. contraindications: in general, patients with fever, impaired immune function, allergic constitution, active tuberculosis, pregnancy or lactation, epilepsy, skin diseases, and acute and chronic diseases are often restricted in vaccination, depending on the type of vaccination, and the doctor needs to judge whether it affects vaccination; 2. vaccine pairing contraindications: some vaccines cannot be Some vaccines cannot be given at the same time or require a long interval before other vaccines can be given again. Commonly, polio vaccine cannot be administered at the same time with BCG vaccine and Pertussis vaccine, etc. New crown vaccine often cannot be administered at the same time with influenza vaccine and HPV vaccine. The main reason is that the simultaneous stimulation of the immune system by both vaccines may cause or aggravate post-vaccination adverse reactions and affect the health of the patient. Before vaccination, the relevant situation should be explained with the doctor; 3. Others: Patients are not recommended to take a shower on the same day after vaccination, so they can clean the local skin one day before vaccination, which can effectively reduce bacteria from attacking the vaccination site and causing infection, pain and other symptoms. In addition, it is recommended to ensure sufficient rest before vaccination and avoid staying up late and smoking. A light and easily digestible diet will help reduce the burden on the gastrointestinal tract and reduce or avoid adverse reactions to the vaccine.