Under normal circumstances, fever can resolve itself within 2-3 days after diphtheria vaccination, but there are individual differences in the exact time. Pertussis vaccine consists of pertussis vaccine, diphtheria toxoid and tetanus toxoid, which can effectively prevent pertussis, diphtheria and tetanus. Pertussis vaccine is an inactivated vaccine (i.e., the bacteria or virus has lost its ability to reproduce and is generally not harmful to humans) and will produce a corresponding immune response, including fever, which is a normal immune phenomenon. If the vaccination site is inadvertently infected, the fever may last longer and may not heal on its own, requiring treatment of the infection. To relieve the baby’s discomfort, physical cooling can be used during the fever. If the fever is within 38.5℃, physical cooling can be done by using antipyretic patches and warm water baths; if the fever exceeds 38.5℃, antipyretic drugs can be taken under the guidance of a doctor. If the fever does not disappear or worsens after 3 days, you need to consult a pediatrician for treatment.