The first thing to consider is that the redness and swelling of the arm after the vaccination may be caused by an infection in the eye of the needle, which is mainly caused by the patient’s lack of attention in the shower, resulting in the local eye of the needle getting infected with sewage. It is recommended that the patient must take anti-infective drugs, such as cefradine capsules or amoxicillin capsules, which can effectively control the local infection. Once the local infection is controlled, the redness and swelling will subside on its own. In addition, it is possible that the patient may be allergic to the vaccine, which may also cause local redness and swelling, which may affect the preventive effect of the vaccine, so it is recommended that the patient can go to the hospital in time for the relevant examination, and if there is indeed an allergy to the vaccine, it is recommended that the patient promptly change to other drugs for injection, prevention, to avoid causing disease infection.