If the hepatitis B core antibody is lower than the normal reference value, and the hepatitis B surface antigen and hepatitis B e antigen or e antibody are also negative, it means that you have not been infected with hepatitis B virus in the past and only need to be vaccinated against hepatitis B. If the hepatitis B core antibody is low, lower than the normal value, but the hepatitis B surface antigen and/or hepatitis B e antigen or e antibody are positive, it indicates that you may be infected with hepatitis B virus. If the hepatitis B core antibody is low and below normal, but the hepatitis B surface antigen and/or e antigen or e antibody is positive, it indicates that the person may be infected with hepatitis B virus, and further examination of hepatitis B virus DNA and liver function is needed. If the hepatitis B core antibody is low but higher than the normal reference value, it means that hepatitis B virus infection may have occurred and further tests are needed to clarify.