Since the 2010 foot and mouth (FMD) epidemic, the Korean government has applied a FMD vaccination to pigs. A FMD vaccine is injected to pigs by intramuscular (IM) route. One of the drawbacks in FMD vaccine IM injection is that it would result in an abnormal meat on the injection spot. An abnormal meat due to FMD vaccine IM injection would cause economic loss to pig farmers. An intradermal (ID) injection would be an alternative method for FMD vaccination. The goal of current study was to compare the antibody formation rate between FMD vaccine IM injection and ID injection. The antibody formation rate was measured by the FMD serotype O vaccination percent inhibition (PI) value. In total 350 pigs (175 for FMD vaccine IM injection and 175 for FMD vaccine ID injection) were included in the study. In results, the PI values of FMD vaccine IM injection group were significantly higher than it of FMD vaccine ID injection group. However, the proportions of pigs with PI value was higher than 50, which is a legislative requirement for marketing pigs, for both FMD vaccine IM and ID injection groups at week 20 or 23 were not significantly different. The current results indicated that a FMD vaccine ID injection could be an alternative method of IM injection.

Seven outbreaks of foot-and-mouth disease (FMD) have occurred in South Korea during the period January 2000-September 2015. The Korean government changed national goal to FMD-free country with vaccination after the November 2010 outbreak when approximately 3.5 million cattle and pigs were culled. With regard to vaccination, Korean pig producers have claimed that the occurrence of injection site reaction (inflammatory or non-inflammatory granuloma) is potentially associated with intensive vaccination campaign since 2011. The present study was undertaken to assess the incidence of injection site lesions in slaughtered pigs caused by FMD vaccination and the corresponding economic losses. Data obtained from two meat packers were classified into 3 vaccination periods: non-vaccination (July-November, 2010, n=96,959); one injection (July-November, 2014, n=162,089); and two injections (March-July, 2015, n=161,928). A total of 420,976 carcasses from 6,526 farms were analyzed. The incidence of the lesions was 18.6% for non-vaccination, 46.5% for one injection, and 73.7% for two injections. Economic loss per head slaughtered due to removal of the lesions was estimated to 1,302 won (US$ 1.1) for non-vaccination, 8,286 won (US$ 7.2) for one injection, and 17,378 won (US$ 15.1) for two injections (converted using 2015 exchange rate where Korean won 1,150 = 1 US$). It was estimated that the national annual losses excluding costs of an FMD vaccine and its application is US$ 115 million for one injection and US$ 241 million for two injections. The adoption of measures that cause minimal tissue damages and economic losses would appear to be of high priority.