Mild fever after group a influenza vaccination is a normal physiological reaction that occurs 10-24 hours after vaccination and usually lasts no longer than 2 days. The reaction after group a influenza vaccination is usually mild, with no serious local or systemic reactions and occasional allergic reactions. If there is no other uncomfortable reaction, no special treatment is needed and close observation can be done. If there is also general discomfort, fever over 39℃, or fever lasting longer than 3 days, it is recommended to take the child to the pediatric department of the hospital in time to check whether there is a cold or other infectious disease. In addition, after vaccination, it is necessary to pay attention to avoid contact with water at the eye of the needle and keep the local area clean to avoid infection and other symptoms.