Prophylactic efficacy of immune serum globulin against hepatitis A.

A remarkable decline in the morbidity of hepatitis A was observed in the members of the Japan Overseas Cooperation Volunteers (JOCV) following inoculation of these volunteer workers with human immune serum globulin (ISG) once every 4-6 months, a program which was started in 1981 on a voluntary basis. The morbidity rate of hepatitis A declined from 3.5% in 1980 to 0.6% in 1983 and 1984. A significant difference in the morbidity of hepatitis A was observed among those who were not. In addition to precautions about drinking water and fresh or uncooked foods, inoculation with ISG for the prophylaxis against hepatitis A is recommended when non-immune subjects from a developed country travel to or stay in developing countries.