Emergence of antigenic variants of Foot-and-Mouth Disease Virusserotype O in Ecuador and preliminary evaluation of a field strain as avaccine candidate

MARADEI E; MALIRAT V; PEREZ BEASCOECHEA, C.; ESPINOZA, A.M.; GALDO NOVO, S.; SMITSAART, E.; SALGADO G.; MATTION, N; RODRIGUEZ TOLEDO, J.; BERGMANN I.E.

VACCINE

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2014 vol. 32 p. 2446 - 2451

0264-410X

Foot-and-Mouth Disease Virus serotype O has been circulating regularly throughout most provinces ofEcuador, one of the two South American countries that still remain endemic, although satisfactory vacci-nation coverage was reported. This study concentrates in the characterization of isolates collected during2008?2011, focusing particularly on the antigenic and immunogenic relationships of the field viruses withthe O1/Campos vaccine strain in use in the region and with an experimental vaccine formulated with arepresentative strain of the 2010 epidemic. The results established that antigenically divergent variantspoorly protected by the vaccine in use emerged and co-circulated in a limited period of time. A monova-lent vaccine formulated with the representative 2010 strain elicited high antibody titers and protectedagainst challenge with homologous virus. In addition, cross-reactive antibodies to predominant virusesin the region were established. In overall this study indicates the ability of the virus to diversify underfield conditions in which a vaccine strain with poor match is applied, and the potential of the selected2010 field virus as a vaccine candidate for incorporation into strategic antigen banks and/or for addi-tion to current formulations for systematic vaccination, in order to prevent the emergence of even moredivergent isolates in the future.