Identification of a novel vaccine adjuvant that stimulates and maintains diphtheria toxoid immunity.

Abstract

Immunomodulation by plant-derived medicines is well-documented with effects on both innate and adaptive immunity. This study reports potent and long-lasting diphtheria toxoid-specific immunity by the botanical medicinal, Rehmannia Six Formula, using an in vivo mouse model of vaccine immunity. A significant vaccine adjuvant effect was observed with an increase in serum anti-diphtheria toxoid total and IgG antibodies following oral administration of Rehmannia Six Formula to mice. This response was antigen-specific and was still detectable six months following botanical medicinal treatment, suggesting that Rehmannia Six Formula could help maintain protective antibody levels in populations where..