Foot-and-mouth disease (FMD), which affects cloven-hoofed animals, is economically important because of its highly contagious nature. FMD virus (FMDV), the causative agent of FMD, involves seven serotypes (O, A, Asia1, C, and SAT 1-3). Serotype Asia1 is unique to the Asian territory and is subdivided into nine genetic groups (G-I-IX) based on nucleotide variations in the VP1 sequence. Asia1 Shamir, the most representative Asia1 vaccine, is not highly protective against the Asia1/MOG/05 (G-V) lineage found in North Korea in 2007. Therefore, we investigated whether a chimeric virus strain (Asia1/MOG/Shamir), in which the VP4, VP2, and VP3 sequences of Asia1/MOG/05 were combined with the VP1 sequence of Asia1 Shamir, can simultaneously protect against both viruses. We determined the optimal viral growth conditions for the commercial utilization of this chimeric virus strain. Of the three types of cell culture media, the Cellvento medium resulted in the highest amount of antigen in the samples. The chimeric strain was proliferated in a small bioreactor to produce a test vaccine, and its immunogenicity was evaluated in pigs. The virus neutralization (VN) titer against the Asia1 Shamir virus was > 1/100 after the second immunization with the chimeric vaccine in pigs. In addition, a single dose of the test vaccine resulted in a VN titer of > 1/100 against the Asia1/MOG/05 strain. Taken together, our chimeric vaccine strain provided sufficient protection against the Asia1/MOG/05 and Asia1 Shamir viruses, suggesting its potential as a novel vaccine for both these strains.

INTRODUCTION
MATERIALS AND METHODS
    Cells and viruses
    Determination of the optimal conditions for FMDVpropagation
    Virus titration
    Quantification of FMDV particles
    Preparation of the vaccine antigen
    VN test
    Statistical analyses
RESULTS
    Determination of the optimal conditions for type Asia1chimeric vaccine strain propagation
    Immunogenicity of the type Asia1 chimeric vaccine inpigs
DISCUSSION
ACKNOWLEDGEMENTS
REFERENCES

• Jae Young Kim(Center for FMD Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin-8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Korea)
• Sun Young Park(Center for FMD Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin-8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Korea)
• Gyeongmin Lee(Center for FMD Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin-8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Korea)
• Sang Hyun Park(Center for FMD Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin-8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Korea)
• Jong-Sook Jin(Center for FMD Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin-8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Korea)
• Dohyun Kim(Center for FMD Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin-8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Korea)
• SooAh Lee(Center for FMD Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin-8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Korea)
• Jong-Hyeon Park(Center for FMD Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin-8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Korea)
• Young-Joon Ko(Center for FMD Vaccine Research, Animal and Plant Quarantine Agency, 177 Hyeoksin-8-ro, Gimcheon-si, Gyeongsangbuk-do, 39660, Korea) Corresponding author