Advax™, a polysaccharide adjuvant derived from delta inulin, provides improved influenza vaccine protection through broad-based enhancement of adaptive immune responses

Advax (TM) adjuvant is derived from inulin, a natural plant-derived polysaccharide that when crystallized in the delta polymorphic form, becomes immunologically active. This study was performed to assess the ability of Advax (TM) adjuvant to enhance influenza vaccine immunogenicity and protection. Mice were immunized with influenza vaccine alone or combined with Advax (TM) adjuvant. Immuno-phenotyping of the anti-influenza response was performed including antibody isotypes, B-cell ELISPOT, CD4 and CD8 T-cell proliferation, influenza-stimulated cytokine secretion, DTH skin tests and challenge with live influenza virus. Advax (TM) adjuvant increased neutralizing antibody and memory B-cell responses to influenza. It similarly enhanced CD4 and CD8 T-cell proliferation and increased influenza-stimulated IL-2, IFN-gamma, IL-5, IL-6, and GM-CSF responses. This translated into enhanced protection against mortality and morbidity in mice. Advax (TM) adjuvant provided significant antigen dose-sparing compared to influenza antigen alone. Protection could be transferred from mice that had received Advax (TM)-adjuvanted vaccine to naive mice by immune serum. Enhanced humoral and T-cell responses induced by Advax (TM)-formulated vaccine were sustained 12 months post-immunization. Advax (TM) adjuvant had low reactogenicity and no adverse events were identified. This suggests Advax (TM) adjuvant could be a useful influenza vaccine adjuvant. (C) 2012 Elsevier Ltd. All rights reserved.