Viral hepatitis A-E belong to the most important infectious diseases worldwide. Viral hepatitis is highly endemic in most developing countries in Africa, South East Asia, and southern America; however also in industrialized countries as Germany hepatitis A, B and C represent a thread which should not be underestimated. In Germany, there are about 20,000 to 40,000 hepatitis A infections every year, most of them acquired abroad; about 50,000 new hepatitis B infections and about 5,000 to 8,000 infections with hepatitis C virus occur every year. About 500,000 individuals are chronic carriers of hepatitis B virus and roughly the same number is supposed to be chronically infected with hepatitis C virus. As possibilities for therapeutic intervention in chronic hepatitis B and C are still limited, immunoprophylactic measures are of particular importance. Passive and active immunization is available for hepatitis A and B but so far not for hepatitis C. Passive immunization by application of specific immunoglobulins gives protection which is effective within a few hours but is limited according to the amount of immunoglobulin to six to twelve months. Active immunization on the other hand induces a specific immune response starting after a delay of usually days or sometimes weeks but nevertheless lasting for at least several years. The combination of both methods, passive-active immunization, has the advantage of immediate protection due to the immunoglobulin which lasts until the active immunization induces an endogenous antibody production.