Hepatitis B 4.5 positive can be vaccinated, and it is recommended that this group of people test the titer of hepatitis B surface antibody, and decide whether it is necessary to take the vaccine after consulting with the physician. The fourth and fifth items of Hepatitis B five tests are Hepatitis B e antibody and Hepatitis B core antibody, which are positive indicating that the patient has been infected with Hepatitis B virus or injected with Hepatitis B vaccine in the past and protective antibodies still exist in the body, but the remaining three items are negative indicating that there is no residual Hepatitis B virus. Although hepatitis B 4.5 positive patients already have protective antibodies in their bodies, the decision to revaccinate is based on the antibody titer. If the antibody titer is greater than 100IU/ml it means that there is already sufficient titer of antibody, and generally there is no need for re-vaccination. If it is between 10 and 100 IU/ml, then a booster shot can be given. If the antibody titer in the patient’s body is lower than 10IU/ml, he/she can be vaccinated with Hepatitis B triple shot vaccine to produce a higher level of antibody to protect the body. Hepatitis B 4.5 positive patients should be tested for Hepatitis B surface antibody titer to decide whether it is necessary to receive Hepatitis B vaccine, and it is recommended to consult the contraindications and precautions for vaccination at the vaccination center before vaccination.