1 Maternal, Newborn, Child and Adolescent Health and Aging Department, World Health Organization, 1201 Geneva, Switzerland. Electronic address: strongk@who.int.
2 Division of Data, Analytics, Planning and Monitoring, UNICEF, New York, NY, USA.
3 Maternal, Newborn, Child and Adolescent Health and Aging Department, World Health Organization, 1201 Geneva, Switzerland.