Prevention of hepatocellular carcinoma by immunization. A WHO meeting.

The evidence for an association between the carrier state of hepatitis B virus infection and hepatocellular carcinoma (liver cell cancer) is now sufficiently strong to justify the use of a vaccine against this infection as a means of preventing this cancer. Effective vaccines are available and have been tested in feasibility studies, and their use in field trials to test their effectiveness against the long-term risk of developing this cancer is now possible. At the present time, only limited quantities of the vaccine derived from human plasma infected by the hepatitis B virus are available, and the development of other types of vaccine is discussed together with the necessary revision of the present requirements for vaccine production. As the studies to assess the prevention of this cancer would require the surveillance of subjects for some years, consideration is also given to the design of field studies with short- and medium-term objectives.