Host Immunization with Recombinant Tick Antigen and Evaluation of Host Immune Response.

Ticks are classified as hematophagous arthropods and transfer a variety of pathogens-such as viruses, bacteria, and protozoans-to vertebrate hosts during blood feeding. These transmitted pathogens cause infectious diseases that continue to affect both humans and animals worldwide. Chemical acaricides are commonly used for tick control to prevent infectious diseases. However, the continuous use of acaricides leads to the emergence of acaricide-resistant tick species; thus, alternative methods for tick control are necessary. Vaccination of vertebrate hosts with tick-derived molecules is considered to be a better alternative against ticks than chemical acaricides because ticks feed on host blood for several days and also concentrate the host blood with antibodies. On the other hand, the host's immune responses against pathogens mainly take two pathways-Th1 (cell-mediated immunity) and Th2 (humoral immunity) pathways. Thus, the vaccine can suggest which immune pathway is more important for vaccination. This chapter describes the procedures of immunizing laboratory animals-mice-with a recombinant tick protein for the preliminary evaluation of its potential as an anti-tick vaccine candidate. In addition, the method of evaluating the antigen-specific antibody production in the host using ELISA is described, as is the subsequent tick-infestation challenge for determining the effectiveness of vaccination.