We plan to develop novel, interdisciplinary approaches to the cultural epidemiology of health conspiracy theories. These include beliefs about secret agendas behind vaccination programs, the side effects of medical treatments, and cover-ups by the government or pharmaceutical industry. Such theories are widespread in many countries around the world and can have highly detrimental and far-reaching effects on the health and wellbeing. The requested funds will be used to develop pilot projects that link micro-level factors, affecting the virulence of these theories (e.g. the psychological properties that make certain beliefs particularly catchy and memorable) and the susceptibility of individuals (e.g. attitudes and prior beliefs), to macro-level, ecological factors that shape the context and vectors of transmission. The projects include designing controlled cultural transmission experiments and a series of ethnographic feasibility studies carried out in five field sites. They will be dir ected by the PI with the support of the CoI, a full-time RA and members of Durham Universitys Special Interest Group on Conspiracy Theories in Health. The goals of the project include establishing proof of concept for the epidemiological approach, a publication setting out future research agendas, and a large grant application.