Usually, the time of appearance of adverse reactions after vaccination is related to the type of vaccination and the type of adverse reactions, in addition to the physical and health conditions of the vaccinated person. Specific adverse reactions and the time of appearance after vaccination mainly include the following: I. Common adverse reactions 1, local adverse reactions: generally after vaccination, immediately or within a few hours of the injection of local redness, swelling, hardness, itching, pain, a very small number of lymphadenitis or lymph node swelling and pain; 2, systemic adverse reactions: generally in the injection of the vaccine for 6-24 hours, there may be fatigue, dizziness, diarrhea , fever and other symptoms. Body temperature is mostly around 37.5 ℃, generally do not need special treatment, in 2-3 days to subside naturally; 3, allergic rash: generally in the injection of the vaccine within a few hours to a few days after the occurrence of hives or maculopapular rash in the face, behind the ears, trunk, limbs and other parts of the rash with obvious itching, allergy is easy to appear. Second, rare adverse reactions 1, anaphylactic shock, laryngeal edema: generally in the injection of the vaccine, immediately or a few minutes after the vaccination can occur, anaphylactic shock can be manifested as a drop in blood pressure, cold extremities, itching, cyanosis, laryngeal edema manifested as tightness in the chest, breathlessness, dyspnea, asphyxia and so on. Resuscitation is not timely life-threatening, the general chance of occurrence is low, but once it occurs, the situation is more critical, which is why the injection of vaccines need to be observed at the scene for 30 minutes; 2, angioneurotic edema: generally occurring within 24 hours of injection of vaccines, manifested as injection of localized redness and swelling, the scope of the gradual expansion of the whole upper arm can be caused by the redness and swelling, and even extend to the face, can be accompanied by other parts of the Urticaria, the chance of occurrence is low; 3, allergic purpura: generally occur 2-7 days after vaccine injection, manifested as a rash of hemorrhagic spots, hemorrhagic spots, can be accompanied by joint pain, generally the chance of occurrence is low; 4, other: if BCG vaccine, local abscesses, BCG lymph node inflammation can be seen 1-6 months after vaccine injection. BCG osteomyelitis or systemic disseminated BCG infection can vary from 1-12 months.