Redness and swelling at the site of vaccination can be treated with hot compresses, and if it worsens, you need to consult a doctor. Localized redness and swelling at the vaccination site after receiving the quadruple vaccine is mainly considered to be caused by adverse reactions to the vaccine. To a lesser extent, the vaccinee can apply localized hot compresses to promote blood circulation, which can be relieved in about 3 to 5 days or subside on its own. However, if there is aggravation, such as pain, pus, etc., the possibility of co-infection is greater. At this time, we need to consult a doctor in time, if necessary, under the guidance of the doctor for the blood routine, local secretion culture and other tests, to clarify the specific causative agent, to take such as penicillin and other antibiotics to carry out targeted anti-infective treatment, to avoid other systemic infectious diseases due to the infection of the inoculation site.