The changing landscape of Marek's disease

Marek's disease virus has been described as an evolving pathogen. As the virus itself has changed in the 30 years since its first isolation, so also have many other aspects of the disease and its control. The disease syndromes induced by virus infection have become generally more acute, more varied in type and occur naturally in a wider spectrum of hosts. There have been at least three distinct generations of vaccines, and a variety of control approaches based on genetics and management. One constant, however, is the deep concern of the poultry industry and research community alike, prompted by the unpredictability of outbreaks and the tendency for the virus to evolve faster than intervention strategies.