The vaccine against the cattle tick, B. microplus, is a recombinant vaccine based on a protein (abbreviated as Bm86) found in the tick at the surface of the gut wall. This protein is an example, along with several derived from H. contortus, of a hidden antigen (the term hidden meaning that the protein is not recognised by the systemic antibody response during natural infection). Vaccination stimulates the production of specific circulating antibodies that are ingested by the target parasite during blood feeding (28). The vaccine effectively suppresses the population of tick larvae available for infestation, rather than protecting individual cattle (69), with a chemical control being applied if tick numbers rise above acceptable limits (70). Vaccinating cattle with the recombinant B. microplus vaccine induces almost total immunity to B. annulatus, demonstrating immunological cross-protection. This immunity is sufficiently strong to inhibit Babesia transmission (43).