The Potential Adjuvanticity of CAvant(R)SOE for Foot-and-Mouth Disease Vaccine

Foot-and-mouth disease (FMD) is a notifiable contagious disease of cloven-hoofed mammals. A high potency vaccine that stimulates the host immune response is the foremost strategy used to prevent disease persistence in endemic regions. FMD vaccines comprise inactivated virus antigens whose immunogenicity is potentiated by immunogenic adjuvants. Oil-based adjuvants have clear advantages over traditional adjuvant vaccines; however, there is potential to develop novel adjuvants to increase the potency of FMD vaccines. Thus, we aimed to evaluate the efficacy of a novel water-in-oil emulsion, called CAvant(R)SOE, as a novel vaccine adjuvant for use with inactivated FMD vaccines. In this study, we found that inactivated A22 Iraq virus plus CAvant(R)SOE (iA22 Iraq-CAvant(R)SOE) induced effective antigen-specific humoral (IgG, IgG1, and IgG2a) and cell-mediated immune responses (IFN-gamma and IL-4) in mice. Immunization of pigs with a single dose of iA22 Iraq-CAvant(R)SOE also elicited effective protection, with no detectable clinical symptoms against challenge with heterologous A/SKR/GP/2018 FMDV. Levels of protection are strongly in line with vaccine-induced neutralizing antibody titers. Collectively, these results indicate that CAvant(R)SOE-adjuvanted vaccine is a promising candidate for control of FMD in pigs.

Automated summary

Foot-and-mouth disease (FMD) is a contagious disease affecting cloven-hoofed mammals, with high potency vaccines being crucial for disease prevention in endemic regions. The study revealed that the novel water-in-oil emulsion CAvant(R)SOE as a vaccine adjuvant significantly enhanced immune responses in mice and pigs when used with inactivated FMD vaccines, providing effective protection against heterologous FMDV challenge. These results suggest that CAvant(R)SOE-adjuvanted vaccines have great potential for controlling FMD in pigs.