Generally speaking, there will be no sequelae after the third vaccination, but some local or systemic adverse reactions may occur, the specific symptoms are related to their own constitution, vaccination and other factors, most of which are transient and can be relieved on their own after a period of time. At present, the common vaccines for the third injection are New Crown Vaccine, 13-valent pneumonia vaccine, rabies vaccine, human papillomavirus vaccine and so on. 1. Common local adverse reactions: redness, pain, hardness, itching and swelling at the vaccination site may occur. 2. Common systemic adverse reactions: low-grade fever, headache, dizziness, limb pain, malaise, cough, loss of appetite, vomiting, diarrhea and so on. 3. Some serious adverse reactions may also occur, such as a drop in blood pressure, pallor, dyspnea and other manifestations after vaccination, and in severe cases, even suffocation due to laryngeal edema. After the third vaccination, you should stay at the vaccination site for 30 minutes, and leave after no discomfort. If minor adverse reactions occur subsequently, they usually disappear in 2-3 days, but if the symptoms are serious or persistent, it is recommended that you go to the hospital in time for medical treatment.