Immunogenicity studies in mice showed that reconstituted powder formulations induced higher IgG immune responses after intramuscular administration than those induced after administration of unprocessed plain antigen. Although the immune response was not as high as after administration of aluminum adjuvanted HBsAg, the immune response to the reconstituted vaccines shifted towards a more balanced Th1/Th2 response compared to the aluminum containing HBsAg formulation.