An additional element in the prevention of introduction and spread of disease is the use of vaccination. The manual does not cover this aspect but the importance of an appropriate vaccination strategy is acknowledged, and vaccination as a possible risk management measure should form part of the overall biosecurity assessment and strategy. The purpose of the manual is to establish a minimum set of biosecurity guidelines, applicable to all poultry producers (including ratites) from hatcheries to the point of delivery at the processor. Commercial enterprises which raise poultry for egg production or for human consumption, or for the purposes of breeding.