One health: From rinderpest to the threat of a four-degree world

This chapter summarizes some of the key issues related to One Health, including its history, named pioneers, some of its defnitions, the milieu which gave it impetus and its relationship with politics, ecology and reductionism. Some of the links between human, animal and environmental health are discussed, including a focus on the now extinct cattle disease, rinderpest. Unusually for a chapter on One Health, it also describes some of the proven and speculative links between infectious diseases and laboratory processes, including vaccine development and trials. The chapter outlines some of the challenges that face One Health practitioners, identifying not only a requirement for more 'joined-up', systemic thinking, but also a need for courage, sometimes in the face of lethal, very powerful opposition. The chapter concludes by suggesting that the greatest challenge for One Health may be to shift its support from rhetoric to reality.