Eckhardt, E., et al. Comparison of the adjuvant effect of AS01, AS03 and alum on the immune response to GMP-grade H5N1 antigen in guinea pigs
Sci Rep, 2026 Aug 20, 16(1):26175. PMID: 42624960
Read this comprehensive comparison of the adjuvant effects of two advanced formulations, AS01 (containing QS-21 saponin and MPL-A) and AS03 (a squalene-based emulsion with tocopherol), against a traditional alum adjuvant in enhancing immune responses to GMP-grade H5N1 influenza vaccine in guinea pigs. It highlights the superior immunogenicity of the saponin-based adjuvants, with both formulations eliciting long-lasting, robust T cell and B cell responses, as well as cross-reactive antibodies, compared to alum or no adjuvant.
Both AS01 and AS03 adjuvants elicited stronger and longer-lasting influenza-specific T cell and antibody responses in guinea pigs compared to alum or unadjuvanted vaccines: Superior immunogenicity, cross-reactive antibodies, generation of xenoreactive and cell-binding Abs (AS03), higher quality of immune response.
- Notably, the research uncovers an unexpected induction of xenoreactive, opsonizing antibodies that bind chicken fibroblasts by the AS03-adjuvanted vaccine, raising questions about mechanisms and safety, yet emphasizing the potent immunostimulatory capacity of saponin-containing adjuvants. This work is interesting for researchers focused on saponin-based adjuvants because it underscores their high efficacy in inducing durable and broad immune responses, aligns with their established clinical use in vaccines like Mosquirix and Shingrix, and advances understanding of their mechanistic and safety profiles, which remain critical for vaccine development.
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