Swelling of the vaccination injection opening may be caused by adverse reactions, localized infections, and other reasons. Usually it can be treated with hydrogen peroxide solution, azithromycin and so on. 1. Adverse reaction: Considering the adverse reaction that occurs when the drug stimulates the local tissues after the vaccination. It is necessary to avoid letting the needle mouth get wet, and do not scratch the red and swollen parts, if necessary, you can use hydrogen peroxide solution and other drugs to apply to the local area. Through the protection of the needle opening, and with the passage of time, the symptoms of swelling will usually be relieved on their own. 2. Localized infection: If the swelling is serious and accompanied by redness and burning, consider localized infection. You can take oral antibiotics to anti-inflammatory treatment, such as azithromycin and other drugs, its role is to inhibit the synthesis of bacteria and proteins, to play the role of antibacterial, so as to alleviate the symptoms of the vaccination injection, to avoid the progression of the disease. If the patient vaccination needle mouth swelling, it is recommended to go to the hospital in time, under the guidance of the doctor for appropriate treatment.