IMIZOL PREMUNITION = type of immunity depending on the presence of infection. Ends with the end of infection. Protection (animals bitten by ticks during chemoprotection period with 2.5ml/100kg of Imidocarb) has been shown to last at least 8 months with B. Divergens. (1 treatment with 2.5ml/100kg per year during tick season for renewal of protection). Protection against B bigemina could be a mix of premunition (~6months) and sterile immunity (immunity in the absence of parasite, ~6 months).