Extended Data Fig. 10: IFX adjuvanted in Quil-A and delivered subcutaneously induces consistent and isotype-balanced anti-IFX titres that are highly protective.
From: An invariant Trypanosoma vivax vaccine antigen induces protective immunity
a, Groups of five mice were immunized with the purified ectodomain of IFX adjuvanted in alum, Quil-A and montanide ISA 201 VG (mont.) using a prime and two-boost regime either intraperitoneally (alum i.p.) or subcutaneously (Quil-A and montanide s.c.). Half-maximal anti-IFX titres were determined by ELISA. Bars are mean ± s.d. IFX adjuvanted with Quil-A administered subcutaneously were able to elicit anti-IFX antibody titres that were as high as those elicited by IFX adjuvanted with alum delivered intraperitoneally. b, Quantification of different anti-IFX antibody isotypes elicited by the different adjuvants. IFX and Quil-A were able to induce a larger proportion of IgG2 isotype subclasses. Data points represent individual mice (n = 5) and bars are mean ± s.d. c, Increased protection to T. vivax challenge using Quil-A in a protein-in-adjuvant vaccine formulation. Fourteen mice were immunized subcutaneously with purified soluble IFX recombinant protein adjuvanted in Quil-A and challenged with transgenic luciferase-expressing T. vivax. Parasitaemia was quantified on the indicated days after parasite challenge using bioluminescence; controls are a cohort of 14 mice treated with adjuvant only. Data points represent individual mice and grey shading indicates bioluminescence thresholds of uninfected mice. Crosses indicate where individuals had to be removed from the study for health reasons thought to be unrelated to the infection. The smaller bioluminescence peaks in four mice corresponding to high bioluminescent readings between days 16 and 24 were caused by bleed-through of bioluminescence signal from the mouse that eventually succumbed to infection.
