World Health Organization

Arcot Ramaswamy Mudaliar, the first president of the UN Economic and Social Council (ECOSOC) in 1946, played a central role in founding the World Health Organization (WHO). Under his presidency, ECOSOC initiated the international conference that established the WHO as a specialized UN agency.

The International Sanitary Conferences (ISC), the first of which was held on 23 June 1851, were a series of conferences that took place until 1938, about 87 years. The first conference, in Paris, was almost solely concerned with cholera, which would remain the disease of major concern for the ISC for most of the 19th century. With the cause, origin, and communicability of many epidemic diseases still uncertain and a matter of scientific argument, international agreement on appropriate measures was difficult to reach. Seven of these international conferences, spanning 41 years, were convened before any resulted in a multi-state international agreement. The seventh conference, in Venice in 1892, finally resulted in a convention. It was concerned only with the sanitary control of shipping traversing the Suez Canal, and was an effort to guard against importation of cholera.

Five years later, in 1897, a convention concerning the bubonic plague was signed by sixteen of the nineteen states attending the Venice conference. While Denmark, Sweden–Norway, and the US did not sign this convention, it was unanimously agreed that the work of the prior conferences should be codified for implementation. Subsequent conferences, from 1902 until the final one in 1938, widened the diseases of concern for the ISC, and included discussions of responses to yellow fever, brucellosis, leprosy, tuberculosis, and typhoid. In part as a result of the successes of the Conferences, the Pan-American Sanitary Bureau (1902) and the Office International d'Hygiène Publique or "International office of Public Hygiene" in English (1907) were soon founded. When the League of Nations was formed in 1920, it established the Health Organization of the League of Nations. …

The WHO's Constitution states that its objective "is the attainment by all people of the highest possible level of health". It also seeks to provide a CRVS (civil registration and vital statistics) system to provide monitoring of vital events (birth, death, wedding, divorce).

Since the late 20th century, the rise of new actors engaged in global health—such as the World Bank, the Gates Foundation, the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) and dozens of public-private partnerships for global health—have weakened the WHO's role as a coordinator and policy leader in the field; subsequently, there are various proposals to reform or reorient the WHO's role and priorities in public health, ranging from narrowing its mandate to strengthening its independence and authority.

In line with a growing global trend, as documented by the OECD and established at the EU, the WHO has embraced increased public participation in health policymaking. This is in alignment with the UN Sustainable Development Goals (SDGs) and other intergovernmental agreements, and means "empowering people, communities and civil society through inclusive participation in decision-making processes that affect health across the policy cycle and at all levels of the system."

During the 1970s, WHO had dropped its commitment to a global malaria eradication campaign, as it was considered too ambitious; it retained a strong commitment to malaria control. WHO's Global Malaria Programme works to monitor malaria cases and potential problems in malaria control schemes. As of 2012, the WHO was to report as to whether RTS,S/AS01, were a viable malaria vaccine. For the time being, insecticide-treated mosquito nets and insecticide sprays are used to prevent the spread of malaria, as are antimalarial drugs – particularly to vulnerable people such as pregnant women and young children.

In 1988, WHO launched the Global Polio Eradication Initiative to eradicate polio. It has also been successful in helping to reduce cases by 99% since WHO partnered with Rotary International, the US Centers for Disease Control and Prevention (CDC), the United Nations Children's Fund (UNICEF), and smaller organizations. As of 2011, it has been working to immunize young children and prevent the re-emergence of cases in countries declared "polio-free". …

The World Health Organization is a member of the United Nations Development Group.

As of March 2026, the WHO has 192 member states: all member states of the United Nations except for Argentina, Liechtenstein and the United States (190 countries), plus the Cook Islands and Niue (non-UN members). No new members have joined since Tuvalu in 2023. A state becomes a full member of the WHO by ratifying the treaty known as the Constitution of the World Health Organization. As of January 2026, it also had two associate members, Puerto Rico and Tokelau. The WHO two-year budget for 2022–2023 is paid by its 194 members and 2 associate members. Several other countries have been granted observer status. Palestine is an observer as a "national liberation movement" recognized by the League of Arab States under United Nations Resolution 3118. The Sovereign Military Order of Malta (or Order of Malta) also attends on an observer basis. The Holy See attends as an observer, and its participation as "non-Member State Observer" was formalized by an Assembly resolution in 2021. The government of Taiwan was allowed to participate under the designation "Chinese Taipei" as an observer from 2009 to 2016, but has not been invited again since. On 20 January 2025, U.S. President Donald Trump signed Executive Order 14155 initiating the 12-month process of withdrawing the U.S. from the WHO, with its completion being certified on 22 January 2026. On 5 February 2025, Argentinian president Javier Milei announced that Argentina would also be withdrawing from WHO, with the completion being certified on 17 March 2026.

WHO member states appoint delegations to the World Health Assembly, the WHO's supreme decision-making body. All UN member states are eligible for WHO membership, and, according to the WHO website, "other countries may be admitted as members when their application has been approved by a simple majority vote of the World Health Assembly". The World Health Assembly is attended by delegations from all member states, and determines the policies of the organization.

The executive board is composed of members technically qualified in health and gives effect to the decisions and policies of the World Health Assembly. …

The seat of the organization is in Geneva, Switzerland. It was designed by Swiss architect Jean Tschumi and inaugurated in 1966. In 2017, the organization launched an international competition to redesign and extend its headquarters.

The World Health Organization operates 150 country offices in six different regions. It also operates several liaison offices, including those with the European Union, United Nations and a single office covering the World Bank and International Monetary Fund. It also operates the International Agency for Research on Cancer in Lyon, France, and the WHO Centre for Health Development in Kobe, Japan. Additional offices include those in Pristina; the West Bank and Gaza; the US-Mexico Border Field Office in El Paso; the Office of the Caribbean Program Coordination in Barbados; and the Northern Micronesia office. There will generally be one WHO country office in the capital, occasionally accompanied by satellite-offices in the provinces or sub-regions of the country in question.

The country office is headed by a WHO Representative (WR). As of 2010, the only WHO Representative outside Europe to be a national of that country was for the Libyan Arab Jamahiriya ("Libya"); all other staff was international. WHO Representatives in the Region termed the Americas are referred to as PAHO/WHO Representatives. In Europe, WHO Representatives also serve as head of the country office, and are nationals except for Serbia; there are also heads of the country office in Albania, the Russian Federation, Tajikistan, Turkey, and Uzbekistan. The WR is a member of the UN system country team which is coordinated by the UN System Resident Coordinator.

The country office consists of the WR, and several health and other experts, both foreign and local, as well as the necessary support staff. The main functions of WHO country offices include being the primary adviser of that country's government in matters of health and pharmaceutical policies.

The regional divisions of WHO were created between 1949 and 1952, following the model of the pre-existing Pan American Health Organization, and are based on article 44 of the WHO's constitution, which allowed the WHO to "establish a [single] regional organization to meet the special needs of [each defined] area". …

In 2024, the Bill & Melinda Gates Foundation was the organization's major private contributor, funding 10% of its budget.