Can cattle and sheep primed with one inactivated bluetongue virus serotype 8 (BTV-8) vaccine be boostered with another?

Groups of cattle and sheep that had received a primary course of vaccination with an inactivated bluetongue virus serotype 8 (BTV-8) vaccine were booster vaccinated 6 or 12 months later with the homologous vaccine or an alternative inactivated BTV-8 vaccine. The neutralising antibody responses in these animals were compared. Antibody titres to the alternative vaccine were significantly higher than to the homologous vaccine (P=0.008) in cattle and there was no significant difference between the antibody responses to alternative and homologous vaccines in sheep (P=0.973). These data indicate that cattle and sheep primed with one inactivated BTV-8 vaccine may be effectively boostered with an alternative commercial inactivated BTV-8 vaccine.