Inactivated bivalent FMD vaccines were prepared using Aluminium hydroxide gel and Montanide ISA50. The prepared vaccines were tested in calves for the humoral immune response using SNT and ELISA after a single dose. Protective serum antibody titers for aluminum hydroxide gel adjuvanted FMD vaccine started at 3rd week post vaccination and persisted till the 16th week then declined under the protective titer for both SNT and ELISA. Protective serum antibody titers for ISA50 adjuvanted FMD vaccine started at 2nd week post vaccination and persisted till the 40th week then declined under the protective titer for both SNT and ELISA. The results revealed that the duration of immunity elicited by gel FMD vaccine was short lived and antibody titer rapidly fall after administration, while oil adjuvanted FMD vaccine gave early protective immune response with longer duration |