Positive 245 is a common term used in infectious diseases to describe three of the five hepatitis B tests as positive, and it is not permanent. Hepatitis B 5 refers to Hepatitis B surface antigen, Hepatitis B surface antibody, Hepatitis B E antigen, Hepatitis B E antibody, and Hepatitis B core antibody, of which 245 positivity refers to Hepatitis B surface antibody positivity, Hepatitis B E antibody positivity, and Hepatitis B core antibody positivity. A 245-positive antibody indicates that the patient has been infected with the virus and has a certain degree of resistance to the virus, and the majority of patients can no longer be infected with the hepatitis B virus within a short period of time. However, these antibodies also have decay period, when hepatitis B surface antibody and hepatitis B E antibody disappear, it means that the human body no longer has the ability to fight against the hepatitis B virus, and at this time, we need to take hepatitis B vaccine again in time to get immunized. In addition, in some extreme cases, such as undergoing tumor chemotherapy, radiotherapy, high-dose immunosuppressive therapy, the body may have a very small amount of virus activated, and reappear surface antigen positive, so 245 positive is not permanent.