Hard lumps at the vaccination site are a common vaccine reaction, which can be relieved on its own without special treatment. In most people, hard lumps at the injection site after vaccination are a normal vaccine reaction, mainly related to the stimulation of local tissues caused by the vaccine. Usually, the localized hard lump after vaccination can disappear on its own in about 1~3 days, without special treatment, and people do not need to worry too much. In addition to hard lumps, localized redness, swelling, pain and other symptoms may accompany the vaccination. For the phenomenon of localized hard lumps after vaccination, it can also be relieved by local hot compresses, magnesium sulfate wet compresses and other ways. If people have localized hard lumps after vaccination, accompanied by skin itching, breathlessness, etc., should be alert to allergic reactions, need to cooperate with the doctor to take emergency measures to prevent accidents. It is recommended that people strengthen local skin care after vaccination, avoiding water, foreign body friction stimulation, to prevent the occurrence of infection.