Vol. 7, No. 3 Supplement, June 2001 Emerging Infectious Diseases 549 The global effort to eradicate polio has become the largest public health initiative in history and is spearheaded by the World Health Organization, Rotary International, the Centers for Disease Control and Prevention, and UNICEF (United Nations Children’s Fund). During 1999, extraordinary progress continued, with the number of polio-endemic countries declining to 30 from 50 in 1998. Of the three poliovirus types, poliovirus type 2 has reached the verge of extinction, with the only known remaining foci existing in northern India. Polio incidence declined to the lowest levels ever in 1999, although the number of reported cases (7,012) increased slightly due to improvements in surveillance and polio outbreaks in Angola and Iraq. Existing challenges in the initiative include maintaining effective activities, gaining access to children in conflict-affected countries, and sustaining political and financial support until certification is achieved in 2005. Maintaining sufficient supplies of oral polio vaccine emerged as an additional challenge during 1999, resulting from marked acceleration of immunization activities. The public-private sector partnership supporting the initiative expanded in 1999 to include the Bill and Melinda Gates Foundation, Ted Turner’s United Nations Foundation, the World Bank, Aventis Pasteur, and De Beers.