Foot and Mouth Disease (FMD) is a highly contagious infection of cloven-footed animals such as buffalo, cattle, sheep, goats and camels and FMD is characterized by high rise of temperature, salivation, smacking of mouth, vesicular lesion in the buccal cavity, inner flares, coronary band and interdigital spaces, memory glands etc. In Pakistan FMI) disease is caused by "0", "A" or "Asia-i" type of the virus of an Aphthovirus of Picornaviridae. The vaccinal serotypes of FMD virus were characterized as "A", "0" and "Asia-i" by virus neutralization test using imported mono-specific rabbit antiserum. Each of the serotypes multiplied rapidly on monolayer of Baby Hamster Kidney -21 (BHK-21) cells.

The BHK-2 I cells were propagated in carrel and roux flasks in MEM 199 containing 10% fetal bovine serum. Heat treated goat serum was equally effective as growth promoter for BHK-21 cell line. The cells rapidly multiplied and formed a monolayer within 72 hours at 37 °C. The cells were harvested using trypsin (0.025%) without affecting the cell viability that was observed by cytometeric as well as by colorimetric assays. The cells were stored in cryogenic containers and revived successfully on 12 months post storage.

The FMD virus isolate ("0", "A" and "Asia-i") grew well on the monolayer of BHK-21 cells and produced more than 106, and i04 units of the Tissue Culture Infective Dose-50 (TCID50) on 5th passage, respectively. Each of the virus serotypes was effectively inactivated using 0.12 % formaldehyde, or 0.004 M of Binary Etyhieneimine (BET).

The inactivated virus suspension was admixed with either oil base, lanolin or aluminium hydroxide gel and homogenized to get stable vaccine preparation. The adjuvant containing vaccines induced detectable level anti-FMDV-VN antibodies titer in buffalo calves on 19 days post-priming. Oil and gel based FMD vaccines induced detectable geometic mean titer (GMT) of the anti-FMDV-CFT antibodies (2-3 and 7-8) on 19 days post vaccination, respectively. The oil and gel based vaccines induced 1: 64 and 1:80 GMT titer of the anti-FMDV-CFT antibodies on 128 and 64 days post-vaccination, respectively and the titer declined there after as 1: 9 and 1: 3.3 on 258 days post vaccination. From this study it can be concluded that oil based vaccine induces the antibody response in buffalo latter than that of gel adsorbed vaccine. Higher titers of the antibodies are retained for comparably longer period of time by oil based vaccines. Moreover, age of buffaloes, animal species and vaccine storage at 4 C exhibited undetectable effects on the antibody response to the vaccine.

The study has indicated that vaccination programs against field infection of FMD in all the domestic cloven footed animal species could be effective way of immunoprophylaxis.