""The name "United Nations", coined by United States President Franklin D. Roosevelt was first used in the Declaration by United Nations of 1 January 1942, during the Second World War, when representatives of 26 nations pledged their Governments to continue fighting together against the Axis Powers."
From Dag Hammarskjöld Library: What is the origin of the "United Nations"? https://ask.un.org/faq/14629
"Founded in 1948, the World Health Organization (WHO) is the United Nations agency dedicated to global health and safety. The Organization connects nations, partners and communities to promote health and serve the vulnerable. WHO works with its Member States to achieve the highest level of health for all people by pursuing universal health coverage."
Available at: https://www.who.int/about/frequently-asked-questions