The Potential Adjuvanticity of CAvant®SOE for Foot-and-Mouth Disease Vaccine

Figures

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  Figure 1. Effect of the CAvant®SOE adjuvant on antigen-specific humoral immune response and serum VN titers in mice. (A) Schematic depiction of experiment strategy. Mice were intramuscularly immunized twice at 0 and 2 weeks with the commercial vaccine or iA22 Iraq-ISA 201 or iA22Iraq-CAvant®SOE and mice without immunization were maintained as a control group (n = 5/group). Blood and spleens were taken at 28 days post-vaccination (dpv). (B) A22 Iraq-specific total IgG titers by indirect ELISA. (C) Type A SP specific antibody titers by type A FMDV SP ELISA. Percent inhibition (PI) > 50 was considered the cutoff of a positive reaction (D) serum virus-neutralizing (VN) antibody titers (log10) to the A22 Iraq strain. The values are presented as mean ± SE. Statistical analyses were performed using ANOVA followed by Tukey’s post hoc test. ns p > 0.05, * p < 0.05, ** p < 0.01.

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  Figure 2. Effect of the CAvant®SOE adjuvant on antigen-specific humoral and cell-mediated immune response in mice. Mice were intramuscularly immunized twice at 0 and 2 weeks with the commercial vaccine or A22 Iraq-ISA 201 or A22Iraq-CAvant®SOE and mice without immunization were maintained as a control group (n = 5/group). Blood and spleens were taken 28 days after vaccination. (A) A22 Iraq-specific IgG1, (B) IgG2a were measured by indirect ELISA and (C) IgG2a/IgG1 ratio was calculated. The number of A22 Iraq-specific (D) IFN-γ spot forming units and (E) IL-4 spot forming units were determined using enzyme-linked immunosorbent spot (ELISPOT) assay. The values are presented as mean ± SE. Statistical analyses were performed using one-way ANOVA or two-way ANOVA with Tukey’s multiple comparisons test. ns p > 0.05, * p < 0.05, ** p < 0.01.

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  Figure 3. Evaluation of protective efficacy following challenge with the heterologous FMD virus in pigs. (A) Schematic depiction of experiment strategy. Pigs were intramuscularly immunized with a single dose of A22 Iraq-ISA 201 or A22 Iraq-CAvant®SOE and pigs without immunization maintain as a control group. Blood samples were collected and challenged with A/SKR/GP/2018 strain at 28 dpv. (B) The changes in clinical score and FMDV RNA levels in sera and mouth swab by qPCR from 0 to 8 days after challenge. (C) VN titer to the A/SKR/GP/2018 strain. VN antibody titer value of >1:32 (1.5 log10) was considered the cutoff of protectable value. The values are presented as mean ± SE. Statistical analyses were performed using two-way ANOVA with Tukey’s multiple comparisons test. * p < 0.05.