- We compared cost–benefit and cost–effectiveness analyses of hepatitis A prevention with immune serum globulin (ISG) vs inactivated hepatitis A vaccine (iHAV) in the Israel Defence Forces. Personnel were grouped according to conditions and duration of service and analyses were performed based on maximum and minimum hepatitis A projected incidences for each group. For standing army soldiers in field units, iHAV is economically superior compared with ISG. For the five other groups studied, the reverse is true. Expected increases in production costs of ISG and expected decreases in costs of iHAV are likely to make iHAV more economical in the future.