Vaccination is not allowed when coughing, and you should not take medication or be sick for three days before or after the vaccination. If you have nasal congestion, runny nose, cough, diarrhea, rash, fever and other phenomena, the vaccination should be delayed as much as possible, because the vaccine belongs to biological agents, and the reaction is different according to the system of each person. If you receive vaccines when you are healthy, the vaccine will work properly and reduce the chance of allergic reactions to the vaccine. If the vaccine is given when you are sick or when you are taking medication, it will affect the effectiveness of the vaccine or aggravate the adverse reactions to the vaccine. When a person is sick, he or she will take medication, and medication is a chemical agent. Biological agents and chemical agents may react with each other, affecting both the therapeutic effect of the medication and the effect of the vaccine. That is to say, the vaccination does not play a preventive role, and some people may also have allergic reactions, which is not conducive to determining whether it is an adverse reaction to the drug or the vaccine.