Foot-and-mouth disease (FMD), caused by the FMD virus, remains a significant threat to livestock worldwide. While current vaccines primarily induce systemic immunity, they have limitations, including delayed antibody (Ab) responses and low titers. To address these shortcomings, we investigated the potential of D-galacto-D-mannan (DGDM) as an oral immunomodulator to enhance both mucosal and systemic immune responses following FMD vaccination. The safety of DGDM was evaluated in mice and pigs through food efficiency ratios and biochemical analyses, confirming its safety for in vivo use. In mice, DGDM administration improved survival rates and preserved body weight after viral challenge. In both mice and pigs, DGDM intake led to a marked increase in both serum Ab and virus-neutralizing (VN) Ab titers, alongside a notable enhancement in the production of secretory IgA (SIgA), a key marker of mucosal immunity. Furthermore, in pigs, DGDM administration also upregulated mucosal immune-related gene expression. These findings demonstrate that DGDM effectively stimulates mucosal immunity, enhancing the overall systemic immune response to FMD and providing a long-lasting immune response. This study underscores the critical role of mucosal immunity in optimizing the efficacy of FMD vaccines, offering a promising strategy for improving vaccine-induced systemic immunity and host protection.

To Cite This Article: Kim HW, Park SH, Ko MK, Shin S, Park JH and Lee MJ, 2025. Mucosal stimulation with D-galacto-D-mannan enhances systemic immunity elicited by the foot-and-mouth disease vaccine. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2025.321