Vaccination is an effective way for children to prevent and control infectious diseases, and vaccination should be carried out on time and according to schedule, but it is also necessary to pay attention to the adverse reactions to vaccination, and usually the following points should be noted: 1. to pay attention to local reactions to vaccination, such as redness, swelling, pain and rash at the vaccination site. 2. to pay attention to systemic-type adverse reactions, and some children with high sensitivity may experience hives or loss of appetite, nausea and vomiting after vaccination. 3, 3. Pay attention to the fact that some children may have a fever after vaccination, which usually does not exceed 38.5℃ and will return to normal within 24 hours, so just pay attention to drinking more water. However, a small number of children have a temporary decrease in resistance due to the reaction of the body after vaccination, which can easily lead to high fever secondary to viral or bacterial infections, or repeated fever for more than 24 hours should go to the pediatric outpatient clinic or emergency clinic to check the cause and be treated for the cause.