Human anaplasmosis caused byAnaplasma phagocytophilumis one of the most common tick-borne diseases in the United States. The black-legged ticks,Ixodes scapularis, vector and transmit this bacterium to humans. In this study, we provide evidence that targetingI. scapularismembrane-bound organic anion transporting polypeptide 4056 (IsOATP4056) with an anti-vector vaccine affects transmission ofA. phagocytophilumfrom ticks to the vertebrate host.Anaplasma phagocytophiluminduces expression of IsOATP4056 in ticks and tick cells. Increased membrane localization of IsOATP4056 was evident inA. phagocytophilum-infected tick cells. Treatment with high dose (10 µg/ml) but not low dose (5 µg/ml) of EL-6 antibody that targets the largest extracellular loop of IsOATP4056 showed cytotoxic effects in tick cells but not in human keratinocyte cell line (HaCaT). Passive immunization, tick-mediated transmission and in vitro studies performed with mice ordered from two commercial vendors and with tick cells showed that EL-6 antibody not only impairsA. phagocytophilumtransmission from ticks to the murine host but also aids in the reduction in the bacterial loads within engorged ticks and in tick cells by activation of arthropod Toll pathway. Furthermore, reduced molting efficiency was noted in ticks fed on EL-6 antibody-immunized mice. Collectively, these results provide a good candidate for the development of anti-tick vaccine to target the transmission ofA. phagocytophilumand perhaps other tick-borne pathogens of medical importance.