Risk communication in public health and health security Risk communication is a core capacity under the World Health Organisation’s (WHO) International Health Regulations (2005) and an important part of modern public health practice. However while international legislative frameworks set the scope of risk communication there is a demand for increasing and improving evidence and skills in risk communication research policy and strategy development evaluation of practice and sustainable capacity building. This cumulative habilitation describes the major contributions to the field of risk communication in public health and health security both at a thematic content level of risk communication research policy and practice and at a broader methodological level. It introduces the new conceptual paradigm of risk communication that moves risk communication from being a technical capacity to convey health risk information to a targeted audience to a governance approach with three strategic axes of information (gathering assessing and sharing) communication (strategies key messages and means of communication) and coordination (at various administrative levels). It introduces a new system to understand risk communication practice by providing a matrix of risk communication activities such as information (listening) communication (relationship building) and coordination (supportive environments) across the lifecycle of an event e.g. outbreak before during and after. Adopting this new perspective can generate innovative insights as demonstrated in the field of antimicrobial resistance. The new paradigm and its methodology can also support strategy development at health policy level and facilitate the assessment of public health security. The Marburg Biosafety and Biosecurity Scale (MBBS) is a framework for rational risk assessment and risk communication and offers a new metric to assess biosafety and biosecurity that can also guide capacity building in these areas. ...