The present investigation was carried out to determine the immunomodulatory effcet of Levamisole on antibody response in

yaks using liquid phase blocking enzyme-linked immunosorbent assay (LPBE) following trivalent oil adjuvant FMD vaccine (O, A, Asia-1). Twenty numbers of apparently healthy and young yaks were divided into two groups viz. groups I and II comprising of 10 animals in each group. All the animals of groups I and II were treated with a single dose of broad spectrum anthelmintic, fenbendazole orally prior to vaccination. The animals of group II were injected with Levamisol, six days prior and after FMD vaccination. On 30 days of post vaccination (dpv), there was a sharp rise to the antibody titres against all the 3 serotypes in animals of both the groups and the protective antibody level (log 10 ≥ 1.8) was maintained up to 90 dpv. A drastic fall of antibody titres against all the 3 serotypes was observed at 120 dpv in animals of both the groups. However, the protective antibody titre against the three serotypes at 180 dpv was maintained in few of the animals of the experimental group II but in Group I the protective titre was found up to 150 dpv only.