The League of Nations Health Organization was established following the First World War inside the League of Nations framework. According to the League's Covenant, it was to "endeavour to take steps in matters of international concern for the prevention and control of disease, even in cases of dire human hardship". Its efforts were hampered by the Second World War, during which United Nations Relief and Rehabilitation Administration also played a role in international health initiatives. During the United Nations Conference on International Organization, references to health had been incorporated into the United Nations Charter and it passed a declaration that an international health body would be set up.
In February 1946, the Economic and Social Council of the United Nations helped draft the constitution of the new body. The use of the word "world", rather than "international", emphasised the truly global nature of what the organization was seeking to achieve. The constitution of the World Health Organization had been signed by all 61 countries of the United Nations by 22 July 1946. It thus became the first specialised agency of the United Nations to which every member subscribed. Its constitution formally came into force on the first World Health Day on 7 April 1948, when it was ratified by the 26th member state. The first meeting of the World Health Assembly finished on 24 July 1948, having secured a budget of US$5 million (then GBP£1,250,000) for the 1949 year. Andrija Stampar was the Assembly's first president, and G. Brock Chisholm was appointed Director-General of WHO, having served as Executive Secretary during the planning stages. Its first priorities were to control the spread of malaria, tuberculosis and sexually transmitted infections, and to improve maternal and child health, nutrition and environmental hygiene. Its first legislative act was concerning the compilation of accurate statistics on the spread and morbidity of disease. The logo of the World Health Organization features the Rod of Asclepius as a symbol for healing.