The International Health Regulations (IHR), first adopted by the World Health Assembly in 1969 and last revised in 2005, are a legally binding rules that only apply to the WHO that is an instrument that aims for international collaboration "to prevent, protect against, control, and provide a public health response to the international spread of disease in ways that are commensurate with and restricted to public health risks and that avoid unnecessary interference with international traffic and trade". The IHR is the only international legal treaty with the responsibility of empowering the World Health Organization (WHO) to act as the main global surveillance system.

In 2005, following the 2002–2004 SARS outbreak, several changes were made to the previous revised IHRs originating from 1969. The 2005 IHR came into force in June 2007, with 196 binding countries that recognised that certain public health incidents, extending beyond disease, ought to be designated as a Public Health Emergency of International Concern (PHEIC), as they pose a significant global threat. Its first full application was in response to the swine flu pandemic of 2009.