The third vaccination has the positive impact of reinforcing the effect of the vaccine and may also have the negative impact of certain adverse reactions. 1. Positive effects: Common vaccines that require a third dose include the New Crown Recombinant Subunit Vaccine and the HPV vaccine. The whole process of vaccination is completed only after the third vaccination, when the body can produce enough antibodies to strengthen the effect of the vaccine, so that it can better prevent the corresponding diseases and have a positive impact on health. 2. Negative effects: most of the vaccines are proteins, due to the differences in the physique of each person, some people may experience localized redness, swelling, pain, low-grade fever, dizziness, nausea, fatigue, muscle aches and other adverse reactions after vaccination, which may have a temporary negative impact on the body. After the third vaccination, you should follow the doctor’s instructions and do not allow the vaccination site to get wet for a short period of time to avoid causing infection. At the same time, you need to pay attention to rest, do not engage in strenuous exercise.