tetano
Editor, Senior Moderator
NPJ Vaccines
. 2026 Apr 28.
doi: 10.1038/s41541-026-01457-1. Online ahead of print.
Quillaja saponaria fraction QS-18 as an adjuvant for liposomal seasonal influenza vaccines
Qinzhe Li[SUP] 1 [/SUP], Zachary Sia[SUP] 1 [/SUP], Yuan Luo[SUP] 1 [/SUP], Wei-Chiao Huang[SUP] 1 2 [/SUP], Hilliard L Kutscher[SUP] 2 [/SUP], Haojun Zhu[SUP] 3 [/SUP], Joaquin Ortega[SUP] 3 [/SUP], Bruce A Davidson[SUP] 4 5 [/SUP], Jonathan F Lovell[SUP] 6 [/SUP]
Affiliations
Saponin fractions from Quillaja saponaria (QS) are promising vaccine adjuvants. Among these, QS-21 is a component in several FDA-approved vaccines, but its limited quantity may present a manufacturing bottleneck. While the related saponin, QS-18, is one of the most abundant fractions, its putative toxicity has historically hindered its clinical development. In this study, we formulated QS-18 into a seasonal influenza virus liposomal nanoparticle protein vaccine comprising contemporary, recombinant hemagglutinin and neuraminidase antigens from influenza A (H1N1), influenza A (H3N2), and influenza B (Victoria lineage). This formulation did not exhibit overt QS-18 toxicity in mice or rabbits. In mice and ferrets, QS-18 adjuvanted particles elicited efficacious antibody responses and provided protection against influenza challenges, comparable to analogous QS-21 adjuvanted liposomes. These findings suggest that more study of QS-18 or QS-18-containing QS fractions is warranted for infectious disease vaccine adjuvant formulations.
. 2026 Apr 28.
doi: 10.1038/s41541-026-01457-1. Online ahead of print.
Quillaja saponaria fraction QS-18 as an adjuvant for liposomal seasonal influenza vaccines
Qinzhe Li[SUP] 1 [/SUP], Zachary Sia[SUP] 1 [/SUP], Yuan Luo[SUP] 1 [/SUP], Wei-Chiao Huang[SUP] 1 2 [/SUP], Hilliard L Kutscher[SUP] 2 [/SUP], Haojun Zhu[SUP] 3 [/SUP], Joaquin Ortega[SUP] 3 [/SUP], Bruce A Davidson[SUP] 4 5 [/SUP], Jonathan F Lovell[SUP] 6 [/SUP]
Affiliations
- PMID: 42049779
- DOI: 10.1038/s41541-026-01457-1
Saponin fractions from Quillaja saponaria (QS) are promising vaccine adjuvants. Among these, QS-21 is a component in several FDA-approved vaccines, but its limited quantity may present a manufacturing bottleneck. While the related saponin, QS-18, is one of the most abundant fractions, its putative toxicity has historically hindered its clinical development. In this study, we formulated QS-18 into a seasonal influenza virus liposomal nanoparticle protein vaccine comprising contemporary, recombinant hemagglutinin and neuraminidase antigens from influenza A (H1N1), influenza A (H3N2), and influenza B (Victoria lineage). This formulation did not exhibit overt QS-18 toxicity in mice or rabbits. In mice and ferrets, QS-18 adjuvanted particles elicited efficacious antibody responses and provided protection against influenza challenges, comparable to analogous QS-21 adjuvanted liposomes. These findings suggest that more study of QS-18 or QS-18-containing QS fractions is warranted for infectious disease vaccine adjuvant formulations.