Control of Rhipicephalus (Boophilus) microplus infestations by the combination of subolesin vaccination and tick autocidal control after subolesin gene knockdown in ticks fed on cattle.

Tick subolesin was shown in immunization trials using the recombinant protein to protect hosts against tick infestations. In this study, we demonstrated that subolesin vaccination and release of ticks after subolesin knockdown by RNA interference (RNAi) could be used for the control of Rhipicephalus (Boophilus) microplus tick infestations in cattle and suggested that the combination of these methods could increase the efficacy of cattle tick control under some circumstances. The greatest tick control was obtained when both release of ticks after subolesin knockdown and vaccination were used concurrently. However, modeling results suggested that vaccine efficacy could be increased if at least 80% of the ticks infesting cattle correspond to subolesin-knockdown ticks. The results of this proof-of-concept trial demonstrated the efficacy of the sterile acarine technique (SAT) through production of subolesin-knockdown larvae by dsRNA injection into replete females for the control of R. microplus tick infestations, alone or in combination with subolesin vaccination.