Homologous and heterologous antibody response of cattle and sheep after vaccination with foot and mouth disease and influenza viruses

Homologous and heterologous antibody response to FMD and influenza vaccines was studied in 37 calves and 45 lambs at the age of 2 months. The FMD and influenza monovalent killed vaccines were administered simultaneously twice. Another group of 18 calves was vaccinated twice, first at the age of 2 months and second at the age of 6 months, with trivalent FMD vaccine. The antibody titers were measured by ELISA and HI after second vaccination, for FMDV and influenza, respectively. The conclusions of this study are summarized as follows. Individuals, lambs and calves, that cross-respond to one heterologous serotype are liable to respond to another heterologous serotype of the same virus. Individuals, lambs and calves, showing double cross-reactivity to one virus (FMDV), are highly liable to show double cross-reactivity to entirely another virus (Influenza). Multivalent vaccines of FMDV are expected to elevate the antibody titers for at least one heterologous serotype (not included in the vaccine) and to detect antibodies for an additional heterologous serotype, not detected otherwise following monovalent vaccination. These results indicate the important role of the host in the spectrum of the specific immune response.