The World Health Organisation (WHO) was founded on 7 April 1948. It replaced the League of Nations’ Health Organisation and is one of the most important organisations within the United Nations (UN). It is based in Geneva, Switzerland, and coordinates international public health policy and responses to public health crises. It also coordinates responses to infectious disease outbreaks, such as the H5 avian influenza (‘bird flu’) and the H1N1 ‘swine flu’ virus pandemic.

The WHO has 194 member states. These appoint delegations to the World Health Assembly, the decision-making body. The assembly appoints a director general every five years, as well as an executive board of 34 qualified health experts.

There are six regional WHO offices worldwide, known as AFRO (Africa), EURO (Europe), SEARO (southeast Asia), AMRO (the Americas), WPRO (western Pacific) and EMRO (eastern Mediterranean).

The WHO’s biggest success to date was the worldwide eradication of smallpox in 1980. This followed a worldwide identification and vaccination campaign. Vaccination is central to the WHO’s ‘yellow card’ programme, an internationally recognised vaccination certificate used for migration to and from some countries affected by endemic diseases.