Preparation and properties of immune-stimulating complexes containing hepatitis B virus surface antigen.

Immune-stimulating complexes (iscoms) have been prepared containing the major S gene products (HBsAg) of the hepatitis B virus genome. Immunization of BALB/c mice with a single dose of hepatitis B iscoms in saline resulted in a high titre antibody response to HBsAg. In contrast, the original HBsAg preparation required an adjuvant to produce equivalent amounts of antibody. Analysis of sera from mice immunized with hepatitis B iscoms revealed antibodies directed against the major a determinants of HBsAg. High secondary antibody responses were observed in immunized animals previously inoculated with a sub-immunogenic dose of HBsAg indicating that hepatitis B iscoms may represent a suitable immunogen for use in individuals in whom a course of immunization with currently licensed hepatitis B vaccines has failed to produce a significant anti-HBs response.