Immune response in rabbits against Rhipicephalus sanguineus.

ABSTRACT

Rabbits immunised with homogenates of unfed larvae and nymphs of the tick R. sanguineus developed significant level of protective immunity to infestation with all the stages of the species. The acquisition of resistance was based on feeding and developmental performance parameters (rejection, moulting percentages and feeding period) of larvae and nymphs. The acquisition of resistance against adults was also measured by feeding and reproductive performance of female ticks viz., rejection percent, engorged female and egg mass weights, engorgement, preoviposition and oviposition periods and efficiency of female ticks in converting their food reserve to eggs and larvae. Sera from larval extract (RLAg) immunised rabbits were strongly positive for anti-RLAg antibodies after 3 weeks of immunisation while nymphal extract (RNAg) immunised rabbits were positive for anti-RNAg antibodies after 2 weeks of immunisation in enzyme linked immunosorbent assay. The immunised rabbits were also positive for immediate type hypersensitivity (ITH) reaction on Intradermal inoculation of RLAg and RNAg.