Hepatitis B is clinically an infectious disease caused by infection of hepatocytes with the hepatitis B virus, and vaccination is an important means of preventing and controlling the onset and transmission of hepatitis B. Hepatitis B vaccination precautions include pre-injection and post-injection, and the vaccinees need to fully understand the precautions and contraindications of hepatitis B vaccine to achieve scientific vaccination. Precautions before vaccination 1. On the day of vaccination, if the recipient’s physical condition is abnormal, including fever, dizziness, headache, nausea, limb weakness and other uncomfortable symptoms, the vaccination should be suspended and the recipient should go to the hospital as soon as possible; 2. 3. The best time for newborns to receive hepatitis B vaccine should be within 24 hours of birth. If the hepatitis B vaccine is not given in time due to some circumstances and the time exceeds one month, it is recommended that parents take their newborns to the hospital to clarify whether there is any infection and then a professional doctor will determine whether the vaccine can be given; 4. If you are already infected or infected, there is no need to vaccinate against hepatitis B because antibodies have been produced in the body. Precautions after vaccination 1. Within 30 minutes after vaccination, the vaccinees need to observe their body at the site to facilitate timely treatment in case of acute allergic reactions such as poor breathing, coughing and dizziness; 2. In order to avoid adverse symptoms such as redness, swelling and local infection at the vaccination site, care should be taken not to scrub the injection site for a short period of time and to keep the vaccination site dry; 3. 3. After vaccination, the recipient should avoid strenuous exercise in the near future to avoid uncomfortable reactions such as headache, limb pain and nausea. Contraindications 1. fever symptoms: if the recipient’s body temperature is >37.5℃ before vaccination, vaccination should be suspended; 2. patients with acute diseases: including angina pectoris, myocardial infarction, acute appendicitis, etc., especially for the recipient who is taking medication, hepatitis B vaccination needs to be avoided; 3. history of serious allergic reactions: if the recipient has serious allergic reactions in previous vaccinations, such as acute facial swelling, fever, rash, etc., the vaccination should be suspended. Hepatitis B vaccination is generally not available if the recipient has had a serious allergic reaction to previous vaccinations, such as acute facial swelling, fever, rash, etc.