Investigation of the optimal medium and application strategy for foot-and-mouth disease vaccine antigen production.

AIMS: For the effective production of 146S particles, which determines foot-and-mouth disease (FMD) vaccine efficacy, we aimed to identify the optimal medium that is easy-to-use, productive and economically affordable for the large-scale production of FMD vaccine. METHODS AND RESULTS: Nine combinations of cell growth media and replacement media were tested for virus propagation. Apart from the replacement strategy, we tested a simple addition strategy involving the addition of 30% v/v of fresh medium to the total spent medium using the Cellvento BHK-200 (Vento). Unlike other tested media that produced poor yields of 146S particles when the spent media were not eliminated, Vento exhibited high productivity with the 30% addition strategy. CONCLUSIONS: Considering its lower price and media consumption compared to those of other media that require media replacement, the 30% addition strategy of Vento is highly effective. Furthermore, owing to its simple application strategy, it makes the scale-up process easy and helps in saving the time and labour involved in spent media removal. SIGNIFICANCE AND IMPACT OF THE STUDY: Through the first comparative assessment of commercial media for the 146S particle recovery, this study suggests the best practical medium for the industrial-scale production of FMD vaccines.

Outbreaks and diagnosis of foot-and-mouth disease serotype O in the Republic of Korea, April-June 2010.

Thirteen outbreaks of foot-and-mouth disease (FMD) were reported in pigs and cattle in Korea between 8 April and 4 June 2010. The FMD virus (FMDV) isolates were of serotype O, indicating that they were related to the virus strains of the Southeast Asia topotype that are circulating in East Asian countries. Animals carrying the viruses were identified by reverse transcriptase-polymerase chain reaction (RT-PCR) during a 29-day period between 8 April and 6 May, 2010. Prior to this outbreak, these FMDVs had not been detected in Korea and may therefore have been introduced from neighbouring countries into Ganghwa Island and subsequently spread inland to other areas, including Gimpo, Chungju and Cheongyang. Tests conducted to lift restrictions on animal movements lead to detection of two additional FMD-positive farms. Through appropriate responses, including swift diagnoses and culling policies, Korea was able to quickly regain its recognition as being free of FMD, without vaccination, by the World Organization for Animal Health (OIE) on 27 September 2010.

Diagnosis and control measures of the 2010 outbreak of foot-and-mouth disease A type in the Republic of Korea.

In January 2010, foot-and-mouth disease (FMD) occurred for the first time in 8 years in Korea. The outbreaks were because of A serotype, different from the O type, which had occurred previously in 2000 and 2002. The FMD outbreaks were identified in seven farms, consisting of six cattle farms where viruses were detected and one deer farm where only FMDV antibody was detected. The seven farms were within 9.3 km of each other. All susceptible animals within 10 km radius of the outbreak farms were placed under movement restrictions for 3-11 weeks. No vaccination took place to facilitate the clinical observation of infected animals and virus detection. After clinical observations and serological tests within the control zones showed no evidence of FMD infection, the movement restrictions were lifted, followed by FMD-free declaration (23 March) at 80 days after the first outbreak on 2 January. This communication describes the outbreak of FMD A serotype, and control measures applied to eradicate the disease in Korea.