Effect of Theileria Parva Marikebuni Vaccine on Feeding and Reproductive Success of Rhipicephalus Appendiculatus
Abstract:
Marikebuni vaccine is a live parasite vaccine used to immunize cattle against East Coast Fever (ECF),which is caused by Theileria parva parasite, transmitted by a three-host tick Rhipicephalus appendiculatus. This study investigated the effect of live parasite vaccine on Rhipicephalus appendiculatus feeding and reproduc tive success.Three groups of ECF naïve calves (n=3 per group) were used: an immunized group receiving 1 ml of Marikebuni vaccine and a long-acting oxytetracycline blocking agent and two control groups receiving either uninfected tick material and the blocking agent or uninfected tick material only. Uninfected adult Rhipicephalus appendiculatus were counted and weighed before and after feeding on the calves and Incubated at 27-28 ⁰C optimum temperature and 80% -85% humidity. Tick feeding success, oviposition success and larval hatchability were analysed using linear regression,logistic regression and ANOVA (p 0.05). However, a signif icant negative relationship occurred between the unfed tick weight and the blood meal imbibed by ticks fed on immunized calves (β = 0.4918, R2 =0.7261, F (1, 7) = 22.21, p = 0. 0.002176). These ticks produced signifi cantly lower egg mass weight compared to controls. (F = 7.993; p-value = 0.023).Immunization reduced the absolute number of viable larvae produced,though the difference was not statistically significant(P>0.05). The vaccine therefore indirectly reduce tick reproductive output, offering potential added value for vector control.
