Immunostimulatory Effect of Levamisole on the Immune Response of Goats to <i>Peste des petits ruminants </i> (PPR) Vaccination

Abstract

The use of Levamisole hydrochloride as an immunostimulant has been successful in the control of certain diseases such as Derzsy’s disease in chicken as well as in increasing lymphocytes and weight gain in pigs. However, its use as immunostimulant in the prevention of Peste des petits ru minants (PPR) in goats has not been investigated. In this study, the use of Levamisole in enhancing immune response to PPR vaccination including its effects on weight gain was investigated among groups of goats (groups A, B, C and D). Virus neutralization test was used to determine the antibody profile in vaccinated goats while the total and differential leucocyte counts and body mass index (BMI) were determined using standard procedures. Goats in group A (Levamisole primed and PPR vaccinated) seroconverted to more than 3-folds of the initial pre-vaccination geometric mean titre (GMT) of neutralizing antibody beginning from second week post-vaccination and remained high throughout the period of the experiment. Similarly, there was significant increase (p < 0.01) in leucocyte production, particularly the lymphocytes following administration of Levamisole with the PPR vaccine. Goats in group B (vaccinated only), also seroconverted to significant GMT value as in group A but the value dropped significantly on the 4th week post vaccination. Group C that was administered Levamisole only, had significant increase in leucocyte value following treatment with the drug. Group D (control) had no significant change in their leucocyte. Groups C and D had no significant change in GMT throughout the period of experiment. Apart from group C, there was no significant change (p > 0.05) in BMI of animals in other groups throughout the period of the experiment. The results of this study further confirm the immunostimulatory effect of Levamisole when used in combination with a vaccine.