The third injection generally refers to the third injection of New Crown Vaccine. Reactions include serious adverse reactions such as drop in blood pressure, dyspnea, etc. and general adverse reactions such as fever. 1. Serious adverse reactions: patients will show symptoms of pallor, drop in blood pressure, dyspnea, or even asphyxia due to edema of the throat. The above symptoms are generally uncommon and most often occur within half an hour after vaccination. 2. General adverse reactions: localized swelling and redness of the skin in the injection area, hardness and itching. Patients are advised to avoid touching the skin in the injection area with water on the day after the third injection to avoid aggravating the adverse reaction. Systemic reactions include the development of low-grade fever, dizziness and nausea, limb pain, and loss of appetite. Therefore, in order to avoid serious adverse reactions, it is necessary to stay at the vaccination site for 30 minutes after vaccination, and leave after no discomfort, so as to facilitate the timely administration of rescue in case of serious adverse reactions. After vaccination, patients are advised to choose a light diet and avoid spicy and stimulating foods. Pay attention to rest and avoid overwork.