Hepatitis B 245 refers to Hepatitis B surface antibody, Hepatitis B e antibody and Hepatitis B core antibody, which are not immune for life. Hepatitis B surface antibody, Hepatitis B e antibody and Hepatitis B core antibody are positive, which means that there are antibodies in the body that can fight against the Hepatitis B virus, and the more of these three types of antibodies, the higher the value is accordingly, and the stronger the protection for the human body. However, it will not keep on increasing, in case of low immunity or cold and sickness, the protective antibody against hepatitis B will be weakened. Some people develop hepatitis B antibodies after receiving hepatitis B vaccination because the hepatitis B vaccine can enhance the protective antibodies in the body, thus achieving a certain preventive effect. For people who do not strictly follow the requirements of hepatitis B vaccination, the hepatitis B antibody in the body will gradually weaken and cannot achieve the preventive effect. It is recommended to go to the hospital regularly for hepatitis B two-to-half examination, and if it is found that the antibody is weak, it should be vaccinated with hepatitis B virus vaccine under the instruction of doctor.