Abstract
In South Korea, pigs were vaccinated once between 8 and 12 weeks of age because of the injection-site granulomas. Therefore this study was performed to determine the optimal age for single vaccination of growing pigs with the currently used type O FMD vaccine. With 498 pigs divided into four groups, seroprevalence of the antibody was analyzed with enzyme-linked immunosorbent assay. Although double vaccination is necessary to completely protect growing pigs from FMD virus infection with the current vaccine, the age of 8 weeks can be considered as the optimal age for piglet vaccination if the booster injection is unavailable.