Practical aspects of poultry vaccination

The immune system evolved to free multi-cellular organisms from invasive organisms that can cause disease. Similar to the mammalian immune system, that of chickens, the best studied among birds, is a multilayered network of cells and molecules and their interactions, which becomes active in a sequential form after the organisms invade the host and that play different roles. The chicken immune response, like that of mammals, can be divided into innate or non-specific and adaptive or specific, both of which are necessary for an effective vaccine-induced immunity as outlined in this chapter. Live-attenuated and killed vaccines are widely used in the control of infectious diseases of poultry. The practical application of poultry vaccination strategies and the use of vector vaccines are reviewed as well