Vaccination in China can be divided into two categories, the first category of vaccines refers to vaccines provided by the state free of charge, including BCG, hepatitis B vaccine, polio vaccine, polio vaccine, New Crown vaccine, etc. The second category of vaccines refers to self-funded, voluntary vaccinations, including pneumonia vaccine, influenza vaccine, etc. The following kinds of contraindications and precautions are common, but whether the specific vaccination can be determined by a doctor: I. Contraindications Those who are severely allergic to any of the components of the vaccine are prohibited from receiving the vaccine. For example, people who are severely allergic to eggs cannot be vaccinated against influenza; 2. People with serious or acute diseases, unstable organism functions, such as fever, allergy, post-operative recovery, or platelet dysfunction, epilepsy, immunodeficiency diseases, etc., generally cannot be vaccinated. However, there are some important vaccines that do not have this contraindication, such as rabies vaccine. Precautions: 1. Before vaccination: Patients need to clearly inform the doctor of their allergy history, family genetic history, the existence of chronic medical history, the existence of abnormalities at the skin site of vaccination, such as bumps, scars, rashes, etc., and also self-report whether they have been using medication recently, as well as the name and length of medication, so that the doctor can determine whether they are suitable for vaccination; 2. 3. After vaccination: Generally, it is necessary to stay for about 30 minutes after vaccination. Patients are not recommended to take a bath or swim on the same day to avoid water exposure and infection at the injection site. Systemic symptoms such as fever, dizziness, nausea, etc., and local redness, swelling and pain of the injection site may be normal, and can usually heal on their own in a few hours or 1-2 days. At the same time, patients should eat a light diet, consume more fresh fruits and vegetables, avoid eating spicy and stimulating foods such as chili, seafood, fried chicken, etc., as well as smoking, drinking alcohol, drinking strong tea, and should also avoid bad habits such as staying up late to ensure adequate rest.