Inactivated whole virus
foot-and-mouth disease (FMD)
vaccines are used worldwide for protection against FMD, but not all
vaccines induce protection against all genetic variants of the same FMD virus serotype. The aim of this study is to investigate whether the "breadth" of the antibody response against different strains of the same FMD virus serotype in cattle could be improved by using a different adjuvant, a mix of
antigens and/or different routes of administration. To this end, six groups of five cattle were vaccinated with different FMD virus serotype A strain
vaccines formulated with
Montanide ISA 206 VG adjuvant. Antibody responses for homologous and heterologous cross-reactivity against a panel of 10 different FMD virus serotype A strains were tested by a liquid-phase blocking ELISA. Results of cattle vaccinated with ISA 206 VG adjuvanted
vaccine were compared with results obtained in a previous study using
aluminium hydroxide-
saponin adjuvant. No significant effect of adjuvant on the breadth of the antibody response was observed, neither for mixing of
antigens nor for the route of administration (subcutaneous vs. intradermal). Comparison of
antigen payload, however, increased both homologous and heterologous titres; a 10-fold higher
antigen dose resulted in approximately four times higher titres against all tested strains. Our study shows that breadth of the antibody response depends mainly on the
vaccine strain; we therefore propose that, for
vaccine preparation, only FMD virus strains are selected that, among other important characteristics, will induce a wide antibody response to different field strains.