Immunological approaches to the control of ticks

Abstract

It has now been amply demonstrated that it is possible to induce an immunologically-mediated resistance to several tick species using crude extracts. This is the first step on a long road to a practical means of tick control. The next step must be the identification of protective antigens and this work has hardly been started. It must be remembered that one cannot even gauge the eventual effectiveness of a vaccine from experiments with crude extracts: as antigen purification proceeds, the effectiveness may increase (due to the removal of irrelevant antigens) or fall (due to the separation of a multiplicity of synergistic antigens). On a more optimistic note, it has now been shown that immunity to ticks can be produced using concealed antigens. This has several possible advantages. It may be intrinsically more effective than naturally-acquired immunity; it may act synergistically with naturally-acquired immunity and finally, and this is pure speculation, it may be harder for the prasite to circumvent than naturally-acquired immunity. In any event, one may perhaps be cautiously optimistic that an immunological alternative to the chemical control of ticks may be developed in the not-too-distant future. © 1986.