Efficacy of a high quality O 1 /Campos foot-and-mouth disease vaccine upon challenge with a heterologous Korean O Mya98 lineage virus in pigs

GALDO NOVO, S.; MALIRAT, V.; MARADEI, E.D.; PEDEMONTE, A.R.; ESPINOZA, A.M.; SMITSAART, E.; LEE, K.N.; PARK, J.H.; BERGMANN, I.E.

VACCINE

ELSEVIER SCI LTD

Año: 2018 vol. 36 p. 1570 - 1576

0264-410X

In 2010 serotype O foot-and-mouth disease virus of the Mya98 lineage/SEA topotype spread into most East Asian countries. During 2010?2011 it was responsible for major outbreaks in the Republic of Korea where a monovalent O/Manisa vaccine (belonging to the ME-SA topotype) was applied to help control the outbreaks. Subsequently, all susceptible animals were vaccinated every 6 months with a vaccine containing the O/Manisa antigen. Despite vaccination, the disease re-occurred in 2014 and afterwards almost annually. This study focuses on the in vivo efficacy in pigs of a high quality monovalent commercial O 1 /Campos vaccine against heterologous challenge with a representative 2015 isolate from the Jincheon Province of the Republic of Korea. Initially, viral characterizations and r 1 determinations were performed on six viruses recovered in that region during 2014?2015, centering on their relationship with the well characterized and widely available O 1 /Campos vaccine strain. Genetic and antigenic analysis indicated a close similarity among 2014?2015 Korean isolates and with the previous 2010 virus, with distinct differences with the O 1 /Campos strain. Virus neutralisation tests using O 1 /Campos cattle and pig post vaccination sera and recent Korean outbreak viruses predicted acceptable cross-protection after a single vaccination, as indicated by r 1 values, and in pigs, by expectancy of protection. In agreement with the in vitro estimates, in vivo challenge with a selected field isolate indicated that O 1 /Campos primo vaccinated pigs were protected, resulting in a PD50 value of nearly 10. The results indicated that good quality oil vaccines containing the O 1 /Campos strain can successfully be used against isolates belonging to the O Mya98/SEA topotype.