VSA 1

VSA 1 is a semisynthetic analog of QS-21, serving as a saponin adjuvant. It enhances antigen-specific IgG1 and IgG2a immune responses in BALB/c mice, indicating a mixed Th1/Th2 immune response. VSA 1 significantly increases vaccine efficacy following initial immunization and boosts homologous protection.

C(O[C@H]1[C@H](O[C@H]2[C@H](O)[C@H](O[C@H]3[C@H](O)[C@@H](O[C@H]4[C@H](O)[C@@H](O)[C@H](O)CO4)[C@H](O)[C@@H](CO)O3)[C@@H](O[C@H]5[C@H](O)[C@@H](O)[C@H](O)CO5)[C@H](C)O2)[C@@H](O)[C@@H](O)[C@@H](C)O1)(=O)[C@]67[C@](C=8[C@@](C)(CC6)[C@@]9(C)[C@](CC8)([C@]%10(C)[C@@](CC9)([C@@](C=O)(C)[C@@H](O[C@H]%11[C@H](O[C@@H]%12O[C@H](CO)[C@H](O)[C@H](O)[C@H]%12O)[C@@H](O[C@H]%13[C@H](O)[C@H](O)[C@@H](O)[C@H](C)O%13)[C@H](O)[C@@H](C(NCCCCCCCCCCCC)=O)O%11)CC%10)[H])[H])(CC(C)(C)CC7)[H]