Redness, swelling and hardness of the wound after vaccination can be observed regularly, localized hot compresses, and serious cases should go to the hospital. Clinically, many vaccines, including BCG, DPT vaccine, new coronavirus vaccine and other vaccines after the injection is possible to appear local redness, swelling and hard lumps, this is due to the vaccine-induced local reactions, most of which can be gradually improved with the prolongation of time, do not need special treatment. If there is redness, swelling and hard lumps, and accompanied by pain, this can be appropriate local use of warm towels or hot water bags for hot compresses. In addition, you can also use potato chips to reduce local swelling. If the symptoms of redness, swelling, heat and pain are more serious, and accompanied by unbearable itching, you should go to the hospital as soon as possible, there may be a local wound infection or severe allergic reaction. At this time should be under the guidance of the doctor to deal with.