Developing a Next-Generation Vaccine Adjuvant System through Rational Design to Alleviate AS01 Adjuvant Deficiency

Vaccine adjuvants play a crucial role in enhancing immunogenicity, with AS01 distinguishing itself due to its potent immunostimulatory properties. However, its broader application in vaccines is limited by several critical challenges, including the scarcity of QS-21, stringent storage requirements, and inherent toxicity. To address these challenges, the present study focuses on the development of novel nonliposomal adjuvant systems, specifically BST01 and BST02, utilizing simplified QS-21 derivatives. The design of these new adjuvants aims to achieve cost-effective synthesis, reduced storage constraints, improved immunogenicity, and decreased hemolytic toxicity. The results show that BST01 and BST02, when coadministered with antigen, induce antibody titers comparable to those of AS01. Collectively, these findings demonstrate that BST01 and BST02 not only mitigate the limitations associated with AS01 but also represent promising candidates for next-generation vaccine adjuvants, demonstrating enhanced efficacy, improved practicality─particularly with respect to storage convenience, and increased safety.