Kinetics of foot-and-mouth disease antibody response in cattle vaccinated with FMD-HS-BQ combined vaccine under field condition.

Foot-and-mouth disease (FMD), Hemorrhagic septicemia (HS), and Black quarter (BQ) are economically important diseases of livestock and wildlife species worldwide, with vaccination serving as the primary control strategy. This study examined the development and duration of FMD antibody responses in cattle administered a trivalent FMD-HS-BQ vaccine under field conditions. Thirty cattle were allocated to three groups: Group 1 consisted of naïve calves (6 receiving a booster vaccination and 6 without a booster); Group 2 included adult cattle with an unknown vaccination history (6 with a booster, 6 without a booster); and Group 3 served as unvaccinated controls (6 animals). Blood samples were collected on days 0, 28, 120, 240, and 365 following initial vaccination, and anti-FMDV antibody levels were measured using solid-phase competitive ELISA. The combined vaccine stimulated anti-structural protein antibody production against FMDV in cattle, with antibodies remaining detectable through day 365 and beyond in animals receiving booster vaccination. Conversely, antibody levels in non-boosted animals started declining after day 120. Virus neutralization testing confirmed the presence of protective neutralizing antibodies on day 365 in cattle that received booster doses. These findings suggest that regular administration of the FMD-HS-BQ combined vaccine at wildlife-livestock interfaces could provide effective FMD protection while offering economic advantages through reduced vaccination costs, labor requirements, and stress on both animals and handlers.