1.Local reaction of vaccine: local redness, swelling and pain of injection, which lasts about 1-3 days, with good prognosis and generally no treatment. 2.Systemic reaction of vaccine: fever, dizziness, chest tightness, palpitations, the incidence is low, generally 1-3%, and can be improved after rest; symptomatic treatment can be given to those with higher fever. 3, allergic reactions: there may be rash (maculopapular rash, urticaria or wind-blown rash), in severe cases, there may be a drop in blood pressure, respiratory distress, laryngeal edema. The incidence of this reaction is extremely low, currently 2/5000000, the need for timely resuscitation treatment. In conclusion, the incidence of side effects of influenza A H1N1 vaccination is low and does not differ from the classical vaccination.