Effect of levamisole administration on bluetongue vaccination in sheep

Levamisole is an anthelmintic drug with immunostimulant properties when administered at repeated doses of 2.5 mg/kg prior to a vaccine being administered. In order to assess the effect of levamisole administration on bluetongue (BT) vaccination in sheep, four groups of unvaccinated pregnant sheep (8 sheep per group) were used. Group A received vaccine only; Group B received levamisole+vaccine; Group C received Levamisole only; Group D was a non-treated control. Levamisole (Citarin L-10%) was administered three times weekly at an initial dose of 5.0 mg/kg of body weight and subsequently at 2.5 mg/kg of body weight. There was a significant decrease in faecal egg count of gastrointestinal strongyles in Groups B and C. At the beginning of the trial, all animals were serologically negative for BT antibodies; after vaccination, there was a difference in antibody response in animals in the treated groups. Significantly, more animals in Group B developed BT antibodies following vaccination than those in Group A. In conclusion, levamisole appeared to have an immunostimulating effect on the response of sheep to BT vaccination.