The World Health Organization (WHO) is a specialized agency of the United Nations (UN) that is concerned with international public health. It was established on 7 April 1948, with headquarters in Geneva, Switzerland. Its predecessor, the Health Organization, was an agency of the League of Nations. The constitution of the World Health Organization had been signed by all 61 countries of the United Nations by 22 July 1946, with the first meeting of the World Health Assembly finishing on 24 July 1948
Since its creation, WHO has been responsible for playing a leading role in the eradication of smallpox which is An acute, highly infectious, often fatal disease caused by a poxvirus. Its current priorities include:
WHO is responsible for the World Health Report, a leading international publication on health, the worldwide World Health Survey, andWorld Health Day which is celebrated every year on 7 April.