Public Health Emergency of International Concern (PHEIC) is defined by WHO under the International Health Regulations (2005) (IHR 2005) as "An extraordinary event which is determined to constitute a public health risk to other States through the international spread of disease and to potentially require a coordinated international response". This definition implies a situation that is: — serious, sudden, unusual or unexpected; — carries implications for public health beyond the affected State’s national border; and — may require immediate international action.