Ticks and tick-borne pathogens have evolved together, resulting in a complex relationship in which the pathogen's life cycle is perfectly coordinated with the tick's feeding cycle, and the tick can harbour high pathogen levels without affecting its biology.
Tick-borne diseases (
TBDs) continue to emerge and/or spread, and pose an increasing threatto human and animal health. The disruptive impacts of global change have resulted in ecosystem instability and the future outcomes of management and control programmes for ticks and
TBDs are difficult to predict. In particular, the selection of
acaricide-resistant ticks has reduced the value of
acaricides as a sole means of tick control.
Vaccines provide an alternative control method, but the use of tick
vaccines has not advanced since the first
vaccines were registered in the early 1990s. An understanding of the complex molecular relationship between hosts, ticks and pathogens and the use of systems biology and vaccinomics approaches are needed to discover
proteins with the relevant
biological function in tick feeding, reproduction, development, immune response, the subversion of host immunity and pathogen transmission, all of which mediate tick and pathogen success. The same approaches will also be required to characterise candidate protective
antigens and to validate
vaccine formulations. Tick
vaccines with a dual effect on
tick infestations and pathogen transmission could reduce both
tick infestations and their vector capacity for humans, animals and reservoir hosts. The development of integrated tick control strategies, including
vaccines and synthetic and botanical
acaricides, in combination with managing drug resistance and educating producers, should lead to the sustainable control of ticks and
TBDs.